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U okviru ovog rada pripravljene su i u čvrstom stanju istražene tetraklorokupratne(II), tetrabromokupratne(II) i tetrakloromanganatne(II) soli izvedene iz monoamina, diamina i triamina različitih geometrijskih karakteristika i kemijskih funkcionalnosti. Poseban naglasak pri istraživnju posvećen je strukturnim karakteristikama priređenih spojeva, njihovim termičkim svojstvima, te odabranim magnetskim i električnim svojstvima. Iz difrakcijske strukturne analize priređenih spojeva, te simetrijske i statističke analize literaturno opisanih primjera, postavljena su geometrijska ograničenja i očekivanja za ovaj tip spojeva, koja su omogućila predlaganje smislenih strukturnih modela iz podataka difrakcije na prahu. Predložena je prava simetrija feroelektrične faze etilamonijevog tetraklorokuprata(II) iz podataka neutronske difrakcije, određene su strukture triju aperiodičnih kristala. Izučene su promjene u strukturi metilamonijevih halogenokuprata(II) uslijed supstitucijskog miješanja na položaju halogenidnog iona. Analizirana su magnetska svojstva slojevitih hibrida u ovisnosti o odabranim gradivnim ionima i dimenzionalnosti anorganske okosnice, te su kvantificirane modulacije u magnetskim svojstvima u supstitucijski miješanim kristalima. In this work, tetrachlorocuprate(II), tetrabromocuprate(II) and tetrachloromanganate(II) salts derived from monoamines, diamines and triamines with different geometric characteristics and chemical functionalities were prepared and investigated in the solid state. An emphasis was given to the structural characteristics, thermal properties, and selected magnetic and electrical properties of prepared compounds. Geometric limitations and expectations were derived for this type of materials from the diffraction structural analysis of prepared compounds, and the symmetry and statistical analysis of those described in the literature, which enabled the proposal of meaningful structural models from powder diffraction data. The true symmetry of the ferroelectric phase of ethylammonium tetrachlorocuprate was proposed from neutron diffraction data. Structures of three aperiodic crystals were determined. Changes in the structure of methylammonium tetrahalocuprates(II) due to substitutional mixing of halide ions were quantified. The magnetic properties of the layered hybrids were analyzed in relation to the selection of building ions and the dimensionality of the inorganic framework. Modulations of the magnetic properties in substitutionally mixed crystals were quantified.

Fibroin svile (FS) jedinstven je i obećavajući prirodni polimer te zbog svoje biokompatibilnosti, biorazgradivosti i netoksičnosti ima velik potencijal za primjenu kao biomedicinski materijal. Unatoč svojoj čvrstoći, sam FS nije prikladan zbog svoje slabe fleksibilnosti. S druge strane, termoplastični poliuretan (TPU) vrlo je poželjan materijal za medicinsku primjenu upravo zbog njegove fleksibilnosti. Problem slabe fleksibilnosti FS-a mogao bi se riješiti miješanjem fleksibilnog TPU-a s FS-om. Cilj ovoga rada bio je pripremiti mješavine na osnovi TPU-a i prirodnog polimera FS-a. Mješavine TPU-a s FS-om pripremljene su umješavanjem FS-a u TPU u omjerima 5, 10, 15 i 20 mas. % FS-a u laboratorijskoj gnjetilici Brabender. Uzorci su dobiveni prešanjem na hidrauličkoj preši. Određena je struktura te toplinska i viskoelastična svojstva čistog TPU-a, FS-a i mješavina TPU/FS primjenom infracrvene spektroskopije s Fourierovim transformacijama (FTIR), diferencijalne pretražne kalorimetrije (DSC), dinamičko-mehaničke analize (DMA) i termogravimetrijske analize (TGA). Dobiveni rezultati FTIR analize pokazuju da je FS ugrađen u TPU matricu. Rezultati dobiveni mjerenjem DSC i DMA pokazali su da se dodatkom FS-a u TPU temperature staklastog prijelaza (Tg) izražene kao Teig, Tmg i Tefg snižavaju zbog smještanja amorfne faze FS-a (asparaginska kiselina) u amorfnu fazu TPU-a, čime dolazi do veće pokretljivosti polimernih lanaca. Temperature taljenja (Tm) izražene kao Teim, Tpm i Tefm u mješavinama TPU/FS neznatno se snižavaju u odnosu na čisti TPU zbog nastajanja slabije uređene kristalne strukture dodatkom FS-a. Toplinska postojanost neznatno se smanjuje dodatkom FS-a zbog njegove slabije toplinske postojanosti., Silk fibroin (SF), a unique and promising natural material extracted from silkworm, has gained much attention for its use as biomedical material, because of its biocompatibility, biodegradability, and nontoxicity. Despite its strength, SF alone is not appropriate because of its poor flexibility. Thermoplastic polyurethane (TPU) is a very desirable material for medical applications because of its flexibility. A solution to the problem of SF’s poor flexibility can be achieved by mixing flexible TPU with SF. The aim of this work was to examine the influence of FS content on the physical and thermal properties of TPU/FS blends. Blends of SF and TPU were prepared with melt mixing of TPU with 5, 10, 15, and 20 wt% of SF in a laboratory Brabender kneading chamber. The specimens of the neat components and their blends were moulded in a hydraulic press. The structural characteristics, thermal, and viscoelastic properties of neat TPU, SF and their blends (TPU/SF blends) were examined by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA). The FTIR results showed that the SF was successfully introduced to TPU matrix. Results obtained with DSC and DMA measurements showed that, when the SF content increased in the TPU/SF blends, the Tg, expressed as Teig, Tmg, and Tefg of the TPU, slightly shifted to lower temperature due to the incorporation of the amorphous phase of FS (aspartic acid) in the amorphous phase of TPU, and mobility of polymer chains increased. The melting temperature (Tm), expressed as Teim, Tpm, and Tefm, decreased because of the less organised crystal structure with the addition of SF. Thermal stability was determined by TGA, which showed that, with the addition of SF, the thermal stability decreased because of the lower thermal stability of SF.

U ovom radu ispitan je utjecaj dodatka kompatibilizatora PEGMA mješavinama PE/PA na toplinska svojstva i stabilnost. Nekompatibilizirane PE/PA i kompatibilizirane PE/PA/PEGMA mješavine pripremljene su u Brabender gnjetilici i hidrauličkoj preši postupkom iz taline. Toplinska svojstva čistih polimera polietilena (PE), poliamida (PA), kompatibilizatora PEGMA, nekompatibiliziranih PE/PA i kompatibiliziranih PE/PA/PEGMA mješavina istražena su primjenom diferencijalne pretražne kalorimetrije (DSC), a toplinska stabilnost određena je primjenom termogravimetrijske analize (TGA). Rezultati DSC analize pokazali su kako miješanje polimera PE i PA u različitim omjerima kao i dodatak kompatibilizatora ne utječe znatno na talište i kristalište PE i PA faze, te nemaju značajan utjecaj na kristalnost PE u mješavinama. Međutim, rezultati pokazuju da prisutnost PE ograničava kristalizaciju PA, posebno uzoraka sa 60% i 80% PE. TGA analizom utvrđeno je da miješanjem polimera PE i PA u različitim omjerima te dodatkom kompatibilizatora PEGMA dolazi do povećanja vrijednosti temperature početka razgradnje poliamida što upućuje na pozitivan učinak kompatibilizatora na toplinsku stabilnost mješavina. In this paper, the effect of addition of compatibilizer PEGMA to PE/PA blends on thermal properties and stability were investigated. Non-compatibilized PE/PA and compatibilized PE/PA/PEGMA blends were prepared in a Brabender kneader and hydraulic press using melt process. The thermal properties of pure polyethylene (PE), polyamide (PA), compatibilizer PEGMA, non-compatibilized PE/PA and compatibilized PE/PA/PEGMA blends were investigated using differential scanning calorimetry (DSC), and thermal stability was determined using thermogravimetric analysis (TGA). The results of the DSC analysis showed that the mixing of PE and PA polymers in different proportions as well as the addition of compatibilizers do not significantly affect the melting point and crystallinity of the PE and PA phases, and do not have a significant impact on the crystallinity of PE in the blends. However, the results show that the presence of PE limits the crystallization of PA, especially the samples with 60% and 80% PE. By TGA analysis, it was determined that by mixing PE and PA polymers in different proportions and by adding the PEGMA compatibilizer, the value of the temperature at which the polyamide begins to decompose increases, which indicates a positive effect of the compatibilizer on the thermal stability of the mixtures.

U svijetu se godišnje proizvede približno jedna milijarda otpadnih guma. Navedeni se broj iz godine u godinu povećava, a samo se 2 % otpadnih guma kao reciklirani materijal koristi u građevinskom sektoru. Uključivanje otpadne gume u građevinsku industriju predstavlja ekološki prihvatljivo rješenje za zbrinjavanje otpadne gume koje promovira održivu gradnju i potiče koncept održive proizvodnje. Detaljnim pregledom literature utvrđene su prednosti korištenja samozbijajućeg betona s recikliranom gumom u odnosu na obični beton s recikliranom gumom te je zaključeno da postojeća znanstvena istraživanja u najvećoj mjeri obuhvaćaju ispitivanja mehaničkih svojstava betona s gumom. Istraživanja termičkih svojstava, svojstava trajnosti te konstrukcijskih elemenata izrađenih od samozbijajućeg betona s recikliranom gumom nisu značajno zastupljena u dostupnoj literaturi, što predstavlja potencijal za buduća eksperimentalna istraživanja. Glavni cilj ovog istraživanja bio je utvrditi utjecaj reciklirane gume na mehanička i termička svojstva, svojstva trajnosti, parametre mehanike loma i mikrostrukturu samozbijajućeg betona te dokazati mogućnost primjene reciklirane gume u nosivim armiranobetonskim gredama zadovoljavajuće mehaničke otpornosti i stabilnosti te poboljšanih svojstava trajnosti. Kako bi se postigao zadani cilj, u prvom koraku provedena su preliminarna eksperimentalna ispitivanja samozbijajućega betona s recikliranom gumom s ciljem definiranja optimalnog sastava betonske mješavine, materijala koji će reciklirana guma zamijeniti, udjela reciklirane gume u sastavu betonsku mješavine te potrebi prethodnoga tretiranja reciklirane gume. U idućem koraku, s ciljem odabira optimalnih mješavina, izrađena je 21 mješavina samozbijajućeg betona s različitim postotnim udjelima reciklirane gume kao djelomične zamjene sitnoga agregata i silicijske prašine kao djelomične zamjene cementu te su provedena ispitivanja svojstava samozbijajućega betona u svježem i očvrsnulom stanju. Provedena su i dodatna eksperimentalna istraživanja ponašanja samozbijajućeg betona s recikliranom gumom pri lomu promatranjem osnovnih parametara mehanike loma. Nakon toga provedena su eksperimentalna ispitivanja odabranih optimalnih mješavina samozbijajućega betona s recikliranom gumom na razini materijala i na razini konstrukcijskih elemenata. Na razini materijala dodatno su ispitana svojstva trajnosti i termička svojstva optimalnih mješavina samozbijajućeg betona s recikliranom gumom te struktura i veza na sučeljku cementnog kamena i prirodnog agregata, tj. reciklirane gume pomoću pretražnoga elektronskog mikroskopa. Na razini konstrukcijskih elemenata ispitano je 12 greda, po tri od svake odabrane betonske mješavine. Na temelju eksperimentalnih rezultata dokazano je da se postotni udjeli reciklirane gume od 10 i 15 % mogu koristiti u nosivim armiranobetonskim elementima bez dodatnih ograničenja vezanih uz svojstva trajnosti, termička svojstava i svojstava mehanike loma. Nadalje, dokazano je da reciklirana guma doprinosi poboljšanju svojstava trajnosti armiranobetonskih greda te da je nosivost armiranobetonskih greda s recikliranom gumom slična ili jednaka nosivosti armiranobetonskih greda bez reciklirane gume., Approximately 1 billion waste tires are produced annually worldwide. This number is increasing from year to year and only 2 % of waste tires are used as recycled material in the construction sector. The inclusion of waste rubber in the construction industry is an environmentally friendly solution for the disposal of waste rubber which promotes sustainable construction and encourages the concept of sustainable production. With detailed literature overview, the advantages of using self-compacting concrete with recycled rubber over ordinary concrete with recycled rubber were identified and conclusion was made that existing scientific research in the majority includes investigation of the mechanical properties of concrete with rubber. Investigations of thermal properties, durability properties and structural elements made of self-compacting concrete with recycled rubber are quite unrepresented in the available literature, which represents the potential for future experimental research. The main goal of this research was to determine the influence of recycled rubber on mechanical, thermal and durability properties, fracture mechanics parameters and microstructure of self-compacting concrete and to prove the possibility of using recycled rubber in load-bearing reinforced concrete beams with satisfactory mechanical resistance and stability and improved durability properties. To achieve the set goal, several steps have been taken. In the first step, preliminary experimental testing of self-compacting concrete with recycled rubber was performed to define the optimal composition of the self-compacting concrete mixture, the replaced material, the proportion of recycled rubber in the self-compacting concrete mixture and the need for pre-treatment of recycled rubber. In the next step, in order to select the optimal mixtures, 21 mixtures of self-compacting concrete with different percentages of recycled rubber as partial replacement of fine aggregate and silica fume as a partial replacement of cement were made and investigation of the self-compacting concrete fresh and hardened state properties were performed. Additional experimental investigation of the fracture behavior of self-compacting concrete with recycled rubber was performed by observing the basic parameters of fracture mechanics. In final two steps, experimental tests of selected optimal mixtures of self-compacting concrete with recycled rubber at the level of material and at the level of structural elements were then performed. At the level of material, the durability and thermal properties of optimal self-compacting rubberized concrete mixtures were examined. Additionally, bond between cement paste and natural aggregate, i.e. recycled rubber was examined with scanning electron microscope. At the level of structural elements, 12 beams were tested, three from each selected concrete mix. Based on experimental results, it has been proven that the percentages of recycled rubber of 10 % and 15 % can be used in load-bearing reinforced concrete elements without additional restrictions related to durability, thermal and fracture properties. Furthermore, it has been proven that recycled rubber contributes to improving the durability properties of reinforced concrete beams and that the load-bearing capacity of reinforced concrete beams with recycled rubber is similar or equal to the load-bearing capacity of reinforced concrete beams without recycled rubber.

U ovom radu ispitivana su toplinska svojstva i toplinska stabilnost polimera: EPDM, PE-HD, PP, PVC, PVAc, PS, PPE, EVA, SAN, ABS-a te Dobeckan poliesterske smole. Polimeri su bili podijeljeni u tri grupe: s obzirom na oblik makromolekule (EPDM, PE-HD i Dobeckan), s obzirom na supstituent vodika (PE-HD, PP, PVC, PVAc i PS) te na kopolimere (PPE, EVA, SAN i ABS). Toplinska svojstva određena su diferencijalnom pretražnom kalorimetrijom (DSC). Toplinska stabilnost polimera određena je primjenom termogravimetrijske analize (TGA). Rezultati analize prve grupe polimera pokazali su kako su EPDM i PE-HD kristalasti, a Dobeckan amorfan polimer. Staklište polimera raste sa stupnjem umreženja polimera, a brzina kristalizacije ovisi o temperaturi kristalizacije. Dobeckan i EPDM razgrađuju se u dva stupnja u odnosu na PE-HD koji se razgrađuje u jednom stupnju. U skladu sa stupnjem kristalnosti i umreženja polimera toplinska stabilnost raste u nizu EPDM

Modifikacija svojstava polilaktidne kiseline (PLA) provedena je dodatkom modificiranih mljevenih koštica masline (mMKM) s ciljem priprave biorazgradljivog kompozita. Uspješno su pripravljeni polimerni kompoziti svih sastava pomoći na ekstruderu s rotirajućim cilindrom. Diferencijalna pretražna kalorimetrija (DSC) je primijenjena u istraživanju utjecaja različitih udjela mMKM na toplinska svojstva i kristalnost PLA. Toplinska svojstva i kristalnost PLA u kompozitima PLA/mMKM ukazuju na slabe interakcije izmeĎu punila i kompozita. Punilo mMKM u kompozitima PLA/mMKM ima samo ulogu zamjene dijela skupljeg materijala s jeftinijim. Toplinska postojanost kompozita istraživana je primjenom neizotermne termogravimetrije (TG). Kompoziti PLA/mMKM se razgraĎuju do tri stupnja razgradnje. mMKM pogoršava toplinsku postojanost polimernih kompozita. Buduća istraživanja treba usmjeriti k promijeni modifikatora ili postupka modifikacije površine MKM kako bi se uspostavile jače interakcije izmeĎu punila i polimerne matrice čime bi se dobila bolja svojstva polimernog materijala. The modification of the properties of poly(lactid acid) (PLA) was performed by adding modified olive stone flour (mMKM) with the aim of preparing a biodegradable composite. Polymer composites of all compositions have been successfully prepared using a rotary cylinder extruder. Influence of different proportions of mMKM on the thermal properties and crystallinity was investigated using differential screening calorimetry (DSC). The thermal properties and crystallinity of PLA in PLA/mMKM composites indicate weak interactions between fillers and composites. The mMKM filler in PLA/mMKM composites has just the role of replacing a part of the more expensive material with a cheaper one. The thermal stability of the composite was investigated using non-isothermal thermogravimetry (TG). PLA/mMKM composites are degraded in three degradation stages. mMKM degrades the thermal stability of polymer composites. Future research should focus on changing the MKM surface modifier or surface modification process to establish stronger interactions between the filler and the polymer matrix to obtain better properties of the polymeric material

Za djelatnu tvar koja se koristi u liječenju shizofrenije, olanzapin, bilo je potrebno pronaći otapalo koje je najpogodnije u vidu morfologije dobivenih kristala. Provedena je kristalizacija s izobutil acetatom, metl izobutil ketonom, etil acetatom i toluenom kao otapalom. Istraživanje je provedeno u šaržnom kristalizatoru. Zbog bolje morfologije kristala i krivulje topljivosti odabran je toluen kao najpogodnije otapalo te se daljnje istraživanje kristalizacije odvija u toluenu. U okviru ovog rada, istražen je utjecaj vrste miješala na morfologiju i granulometrijska svojstva kristala. Korištena su četiri različita miješala, od kojih se s dva miješala postiže aksijalni tok, a s dva radijalni tok. Također, istražen je utjecaj broja okretaja miješala na svojstva dobivenih kristala. Istraživanje je provedeno pri 150, 250 i 350 okretaja u minuti. U svrhu karakterizacije dobivenih kristala olanzapina u različitim uvjetima provedbe procesa, provedena je analiza kemijskog sastava metodom difrakcije rendgenskih zraka, analiza granulometrijskih svojstava gdje je raspodjela veličina čestica određena metodom laserske difrakcije te pomoću FBRM sonde, a morfologija kristala je analizirana optičkim i pretražnim elektronskim mikroskopom pod različitim uvećanjima. Toplinska svojstva kristala olanzapina istražena su diferencijalnim pretražnim kalorimetrom i termogravimetrijskom analizom. For the active pharmaceutical ingredient used in the treatment of schizophrenia, olanzapine, it was necessary to find the solvent which is most suitable in the form of the morphology of the crystals obtained. Crystallization was performed with isobutyl acetate, methyl isobutyl ketone, ethyl acetate and toluene as solvent. The research was conducted in a batch crystallizer. Due to the better crystal morphology and solubility curve, toluene was chosen as the most suitable solvent, and further crystallization research was carried out in toluene. In this work, the effect of the type of mixer on the morphology and granulometric properties of crystals was investigated. Four different mixers were used, of which two mixers achieve axial flow and two radial flow. Also, the effect of the stirrer speed on the properties of the obtained crystals was investigated. The study was conducted at 150, 250, and 350 rotations per minute. In order to characterize the obtained olanzapine crystals under different process conditions, the chemical composition was analyzed by X-ray diffraction, granulometric properties were also analyzed by measuring particle size distribution using laser diffraction method and FBRM probe, and crystal morphology was analyzed by optical and scanning electron microscope with different magnifications. The thermal properties of olanzapine crystals were investigated by differential scanning calorimeter and with thermogravimetric analysis.

Polivinilpriolidon (PVP) je polimer koji od otkrića (Reppe, 1939.) pa sve do danas privlači veliku pažnju zbog svojih iznimnih svojstava. Posjeduje jedinstvenu kombinaciju fizikalnih i kemijskih svojstava kao što su biokompaktibilnost, netoksičnost, kemijska stabilnost, dobra topljivost u vodi i mnogim drugim organskim otapalima, afinitet prema kompleksnim hidrofilnim i hidrofobnim tvarima. Odličan je za stvaranje filma koji je čvrst, transparentan i sjajan, a zbog netoksičnosti i dobre biološke kompatibilnosti koristi se između ostalog kao vezivo za tablete u farmaceutskim aplikacijama. Uslijed istraživanja dobrih svojstava pokazalo se kako PVP bazirani biomaterijali imaju određene nedostatke te se stoga PVP matrici dodaju razna punila. U ovom radu istražen je utjecaj punila, željezovog (III) oksida (Fe2O3) i željeza (Fe), na svojstva PVP polimera. PVP/Fe2O3 i PVP/Fe kompoziti pripravljeni su zamiješavanjem PVP-a s različitim udjelom punila, φ = 0,1; 0,3; 0,5; i 1,0 % u vodenoj otopini. Mjerenjem kontaktnog kuta određena je slobodna površinska energija komponenata te su izračunati parametri adhezije. Uvid u strukturu PVP polimera i kompozita ispitan je optičkom mikroskopijom dok su toplinska svojstva ispitana diferencijalnom pretražnom kalorimetrijom (DSC), mjerenjem toplinske vodljivosti i termogravimetrijskom analizom (TGA). Rezultati su pokazali kako su oba punila dodana u premalim koncentracijama da bi došlo do nekih značajnijih promjena svojstava PVP polimerne matrice, a prema proračunatim parametrima adhezije zaključeno je kako se značajnije interakcije mogu očekivati u kompozitnom sustavu PVP/Fe2O3. Polyvinylpriolidone (PVP) is a polymer which has attracted a great deal of attention since its discovery (Reppe, 1939) until today due to its exceptional properties. It has a unique combination of physical and chemical properties such as biocompatibility, non-toxicity, chemical stability, good solubility in water and many other organic solvents, affinity to complex hydrophilic and hydrophobic substances. It is excellent for creating solid, transparent and glossy film, and due to its non-toxicity and good biocompatibility, it is used, among other things, as a binder for tablets in pharmaceutical applications. By exploring its good properties, it has been shown that PVP based biomaterials have certain disadvantages and therefore various fillers are addedd to the PVP matrix to improve it's properties. In this paper, the influence of iron (III) oxide (Fe2O3) and iron (Fe) filler addition, on the properties of PVP polymer, was investigated. PVP/Fe2O3 and PVP/Fe composites were prepared by mixing PVP with different filler content, φ = 0,1; 0,3; 0,5 and 1,0 %, in aqueous solution. By measuring the contact angle, the surface energy free of the components was determined and the adhesion parameters were calculated. Structure of PVP polymer and composites was determined by optical microscopy and thermal properties of the samples were investigated by differential scanning calorimetry (DSC), thermal conductivity measurement and thermogravimetric analysis (TGA). The results showed that both fillers were added at too low concentrations to cause some significant changes in the properties of the PVP polymer matrix. According to the calculated adhesion parameters it was concluded that stronger interactions can be expected in composite system PVP/Fe2O3.

Polimeri ojačani vlaknima (FRP) nalaze primjenu u zrakoplovnoj, automobilskoj, pomorskoj i građevinskoj industriji. Sastoje se od polimerne matrice u čiju su strukturu uklopljena vlakna koja imaju zadatak poboljšati svojstva matrice. Silikoni su sintetski polimeri elastomernih svojstava, a njihovi nedostaci su mala čvrstoća, otpornost na habanje i vlačnu čvrstoću. Zbog toga se dodatkom punila i /ili vlakana nastoje poboljšati mehanička svojstva silikona. U ovom radu su mehaničkim zamješavanjem pripravljeni kompoziti silikonskog brtvila s različitim masenim udjelom staklenih vlakana (0,1 %, 0,3%, 0,5% i 1%). Metodom kontaktnog kuta ispitivana je slobodna površinska energija i određeni su parametri adhezije kompozita. Diferencijalnom pretražnom kalorimetrijom i termogravimetrijskom analizom određena su toplinska svojstva uzoraka, a utjecaj staklenih vlakana na toplinsku vodljivost silikona ispitan je THB uređajem. Mehanička svojstva pripravljenih kompozita ispitana su rasteznim ispitivanjem. Rezultati su pokazali loša adhezijska svojstva na međupovršini silikon/stakleno vlakno. Toplinskom analizom utvrđeno je povećanje toplinske stabilnosti kompozita povećanjem udjela staklenih vlakana u kasnijim stadijima razgradnje. Dodatak staklenih vlakana nema značajan utjecaj na temperaturu taljenja i kristalizacije silikona, ali utječe na smanjenje toplinske vodljivosti. Optimalna mehanička svojstva uzoraka postižu se pri nižim koncentracijama staklenih vlakana (0.5%). Fiber reinforced polymers are often used in aerospace, automotive, marine and construction industry. They are made from polymer matrix and fibers which improve matrix properties. Silicon sealants are synthethic polymers, elastomers, with poor strength, wear and tensile strength. To improve the mechanical properties, fillers and/or fibers are added to silicon matrix. In this work silicone/glass fibers composites, with different fiber weight ratio (0,1 %, 0,3%, 0,5% i 1%) were prepared by mechanical mixing. Contact angle was used to study the surface free energy and adhesion parametars of the composites. Differencial scanning calorimetry and thermogravimetric analysis were used to determine thermal properties of samples and THB device to investigate glass fiber influence on thermal conductivity of silicone. Tensile tests were preformed in order to investigate mechanical properties of prepared samples. Results showed poor adhesion properties on the silicone/glass fiber interface. Thermal analysis showed that increase in glass fiber concentration leads to increase in thermal stability of composite at later stage of degradation. Based on obtained results, addition of glass fibers does not have significant impact on melting and crystallization temperature. Moreover, addition of glass fibers decreases thermal conductivity. Tensile test results indicate optimal mechanical properties of samples at lower concentration of glass fibers (0,5%).

Pojam adheziva poznat je još od davnina, a upravo su prvi primjenjivi adhezivi bili prirodnog podrijetla, podrazumijevajući sve adhezive na biljnoj i životinjskoj bazi te prirodne gume. Njihova pristupačna cijena i dobra kvaliteta i danas omogućuje široku primjenu, ponajviše u drvnoj i prehrambenoj industriji gdje se najviše cijeni njihovo prirodno podrijetlo. U ovome je radu dan pregled prirodnih adheziva biljnog i životinjskog podrijetla te su ispitana svojstva četiri vrste prirodnih adheziva. Šelak i goveđe tutkalo adhezivi su životinjskog podrijetla a svoju primjenu nalaze u drvnoj industriji i proizvodnji papira, dok su karnauba vosak i guma arabica adhezivi biljnog podrijetla, a svoju primjenu nalaze u prehrambenoj i farmaceutskoj industriji kao zgušnjivači i emulgatori. Na uzorcima prirodnih adheziva provedena su ispitivanja topljivosti u različitim otapalima te su ispitana površinska svojstva mjerenjem kontaktnog kuta na filmovima dobivenim iz otopine adheziva. Strukturna svojstva adheziva ispitana su primjenom FTIR-ATR spektroskopije, a toplinska svojstva primjenom diferencijalne pretražne kalorimetrije (DSC) i termogravimetrijske analize (TGA). Ispitivanja su pokazala značajne razlike između životinjskih i biljnih adheziva. DSC tehnikom utvrđeno je da su goveđe tutkalo i karnauba vosak semikristalne strukture, dok su šelak i guma arabica amorfne strukture. TGA analizom utvrđeno je da se karnauba vosak razgrađuje u jednom stupnju, dok se šelak, goveđe tutkalo i guma arabica razgrađuju u dva ili više stupnja. The term of adhesive has been known since ancient times and the first applicable adhesives were of natural origin, including all plant and animal-based adhesives and natural rubbers. Their affordable price and good quality still enable wide application, especially in wood and food industry where the most valuable worth is their natural origin. In this paper, an overview of natural adhesives of plant and animal origin is given, and the properties of four types of natural adhesives are examined. Shellac and bone glue are animal-based adhesives which are used in wood and paper industries, while carnauba wax and gum arabic are plant-based adhesives which are used in food and pharmaceutical industries as thickeners and emulsifiers. Solubility tests in different solvents were performed on samples of natural adhesives, and surface properties were examined by measuring the contact angle on films obtained from the adhesive solution. The structural properties were examined by using FTIR-ATR spectroscopy, and thermal properties by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results have shown significant differences between animal and plant-based adhesives. The DSC method determined that bone glue and carnauba wax have semicrystalline structure, while shellac and gum arabic have amorphous structure. TGA analysis found that carnauba wax decomposes in one stage, while shellac, bone glue and gum arabic decompose in two or more stages.

Priprava poli(etilen-oksid) (PEO) filmova različitih molekulnih masa provedena je izlijevanjem filmova iz vodenih otopina različitih koncentracija, pri čemu su istraživani optimalni uvjeti otapanja polimera u vodi. Uspješno pripravljene otopine podvrgnute su sušenju pri čemu je cilj bio pronaći i optimalne uvjete sušenja, tj. postupak priprave kvalitetnih suhih filmova. Diferencijalna pretražna kalorimetrija (DSC) je primijenjena u istraživanju utjecaja različitih molekulnih masa, debljina filmova i temperatura sušenja u vakuum sušioniku na toplinska svojstva i kristalnost PEO-a. Uočilo se nastajanje različitih kristala PEO-a u istraživanim filmovima, te se može reći da se određene toplinske značajke filmova značajno ne razlikuju. Toplinska postojanost filmova istraživana je primjenom neizotermne termogravimetrije (TG). Filmovi PEO-a razgrađuju se u jednom stupnju razgradnje i nema razlike u toplinskoj postojanosti filmova obzirom na utjecaja različite temperature sušenja u vakuum sušioniku, različitih molekulnih masa i koncentracija polimernih otopina. Ostvaren je glavni cilj istraživanja koji se odnosi na uspješno uklanjanje otapala iz filmova The preparation of poly(ethylene oxide) (PEO) films of different molecular weights was carried out by casting the films from aqueous solutions of different concentrations, where the optimal conditions for dissolving the polymer in water were investigated. Successfully prepared solutions were subjected to drying, with the aim of finding optimal drying conditions, i.e. the process of preparing quality dry films. Differential scanning calorimetry (DSC) was applied to investigate the influence of different molecular weights, film thicknesses and drying temperatures in a vacuum dryer on the thermal properties and crystallinity of PEO. The formation of different PEO crystals was observed in the investigated films, and it can be said that certain thermal characteristics of the films doesn’t differ significantly. The thermal stability of the films was investigated using non-isothermal thermogravimetry (TG). PEO films are digested in one stage of decomposition and there is no difference in the superior film stability due to the influence of different drying temperatures in vacuum drying, different molecular weights and concentrations of polymer solutions. The main goal of the research related to the successful removal of solvents from films has been achieved.

Polikaprolakton (PCL) je biorazgradivi, semikristalasti polimer niske temperature taljenja koja mu omogućava jednostavnu preradu. Najčešće se koristi u području biomedicine s naglaskom na inženjerstvo tkiva. Iako posjeduje izuzetna fizikalna i biološka svojstva, za poboljšanje toplinskih i mehaničkih svojstava PCL-u se dodaju razna punila. U ovom radu istražen je utjecaj Fe2O3 punila na svojstva PCL polimera. Pripravljeni su uzroci PCL polimera i PCL/Fe2O3 kompozita zamiješavanjem PCL-a s različitim udjelom Fe2O3 punila, φ = 0,1; 0,3; 0,5; i 1,0 % u talini, na dvopužnom ekstruderu. Mjerenjem kontaktnog kuta određena je slobodna površinska energija komponenata te je proračunat termodinamički rad adhezije. Toplinska svojstva uzoraka ispitana su diferencijalnom pretražnom kalorimetrijom (DSC), mjerenjem toplinske vodljivosti i termogravimetrijskom analizom (TGA). Mehanička svojstva određena su rasteznim ispitivanjem. Rezultati su pokazali da dodatak Fe2O3 punila potiče kristalizaciju PCL polimera budući da se entalpije taljenja i kristalizacije povećavaju kod svih kompozitnih sustava te da toplinska vodljivost kompozita raste u odnosu na čistu PCL matricu. Rezultati TG analize pokazali su da dodatak punila utječe na poboljšanje toplinske stabilnosti PCL matrice posebice na početku procesa toplinske razgradnje. Rad adhezije pokazuje porast kod svih kompozitnih sustava što ukazuje na postojanje interakcija na međupovršini matrica/punilo. Kod mehaničkih svojstava nije zabilježen značajan utjecaj dodatka punila. Polycaprolactone is biodegradable, semicrystalline polymer with low melting point which allows it to be simple processing. It is most often used in the field of biomedicine with an emphasis on tissue engineering. Although it has exceptional physical and biological properties, various fillers are added to PCL to improve the thermal and mechanical properties. In this paper, the influence of Fe2O3 filler on the PCL polymer properties was investigated. The samples of PCL polymer and PCL/Fe2O3 composites were prepared by mixing PCL with different amount of Fe2O3 filler, φ = 0,1; 0,3; 0,5; i 1,0 % in the melt, on twin-screw extruder. By measuring the contact angle, the surface free energy and thermodynamic work of adhesion of the samples were determined. Thermal properties were determined by differential scanning calorimetry (DSC), measuring thermal conductivity and thermogravimetric analysis (TGA). The mechanical properties were determined by a tensile test. Results showed that addition of Fe2O3 filler stimulates crystallization of PCL polymer as the enthalpies of melting and crystallization increase in all composite systems and that the thermal conductivity of composites increases compared to the PCL matrix. Results of TG analysis showed that addition of the filler improves thermal stability of PCL matrix especially at the beginning of thermal decomposition. The work of adhesion shows an increase in all composite systems, which indicates the existence of interactions on the matrix/filler interface. In the case of mechanical properties, no significant effect was observed with the filler addition in PCL matrix.

Modificiranje svojstava polilaktida (PLA) provedeno je u Zavodu za tehnologiju nafte i petrokemiju Fakulteta kemijskog inţenjerstva i tehnologije u Zagrebu dodatkom razliĉitih ugljikovih punila (grafitno punilo (CB), grafitne pahulje (CA) i višestijene ugljikove nanocijevi (MWCNT)). Uspješno pripravljeni kompoziti podvrgnuti su na Zavodu organsku tehnologiju Kemijsko-tehnološkog fakulteta u Splitu zagrijavanju i hlaĊenju s trima razliĉitim brzinama zagrijavanja/hlaĊenja (7, 10 i 13 °C min -1 ) zbog simuliranja uvjeta prerade. Simulacija je provedena primjenom diferencijalne pretraţne kalorimetrije (DSC). Istraţivan je utjecaj simuliranih uvjeta prerade na toplinska svojstva i kristalnost PLA kompozita s ugljikovim punilima. Dobiveni rezultati ukazuju da tijekom izrade polimernih izradaka od istraţivanih PLA kompozita treba voditi raĉuna o uvjetima tijekom prerade, vrsti ugljikova punila te udjelu punila u kompozitu koje se mora optimizirati kako bi se dobila ţeljena svojstva PLA kompozita. The modification of the polylactide (PLA) properties was carried out by the Department of Petroleum Technology and Petrochemistry, Faculty of Chemical Engineering and Technology, Zagreb, with the addition of various carbon fillers (graphite (CB), graphite flakes (CA) and multi-walled carbon nanotubes (MWCNT)). Successfully prepared composites were subjected to heating and cooling at the Department of Organic Technology, Faculty of Chemistry and Technology in Split, with three different heating/cooling rates (7, 10 and 13 ° C min- 1 ) to simulate processing conditions. The simulation was performed using differential scanning calorimetry (DSC). The influence of simulated processing conditions on the thermal properties and crystallinity of PLA fillers with carbon fillers was investigated. The results obtained indicate that during the fabrication of polymer products from the investigated PLA composites, processing conditions should be taken into account. The type of carbon filler and the proportion of filler in the composite must be optimized in order to obtain the desired properties of the PLA composites.

Modifikacija poli(etilen-oksida) (PEO) razliĉitih molekulnih masa provedena je dodatkom natrijevog alginata (NaAlg) pripravom pomoću ekstrudera i preše s ciljem dobivanja boljih toplinskih svojstva i kristalnosti PEO-a. Uspješno su pripravljeni samo neki kompoziti razliĉitih molekulnih masa PEO-a s razliĉitim udjelima natrijevog alginata (NaAlg) ekstruzijom i prešanjem. Primjenom infracrvene spektroskopije s Fouierovom transformacijom (FT-IR) nije potvrĊena interakcija izmeĊu PEO-a i NaAlg- a u vidu vodikovih veza. Pomoću diferencijalne pretražne kalorimetrije (DSC) provedeno je ispitivanje utjecaja razliĉitih udjela biorazgradljivog polimera iz obnovljivih izvora (NaAlg) na toplinska svojstva i kristalnost vodotopljivog PEO razliĉitih molekulnih masa, te ovisnost navedenih svojstava o postupku praoblikovanja. Rezultati ukazuju kako NaAlg ne remeti toplinska svojstva i kristalnost PEO-a, te promjena molekulne mase nema znaĉajan utjecaj ali se utjecaj razliĉitih postupaka praoblikovanja ne može zanemariti. Toplinska postojanost kompozita istraživana je primjenom neizotermne termogravimetrije (TG). PEO/NaAlg kompoziti razgraĊuju se u tri stupnja razgradnje. NaAlg pogoršava toplinsku postojanost svih kompozita, te nije utvrĊena razlika izmeĊu utjecaja razliĉitih molekulnih masa i postupaka praoblikovanja. The modification of poly(ethylene oxide) (PEO) of different molecular weight was carried out with addition of sodium alginate (NaAlg) by the extruder and the press, to obtain better thermal characteristics and crystallinity of PEO. Only some PEO/NaAlg composites with different molecular weight of PEO and with extrusion and compression have been successfully prepared. Fourier transform infrared spectroscopy (FT-IR) did not confirm the interaction between PEO and NaAlg in the form of hydrogen bonds. Using differential scanning calorimetry (DSC), the effect of different proportions of biodegradable polymer from renewable sources (NaAlg) on the thermal characteristics and crystallinity of water-soluble PEO with different molecular weights was investigated, as well as the dependence of these characteristics on the preparation process. The results indicate that NaAlg does not change the thermal characteristics and crystallinity of PEO. The change in molecular weight of PEO has no significant effect too, but the influence of different preparation processes cannot be neglected. The thermal stability of the composite was investigated using nonisothermal thermogravimetry (TG). PEO/NaAlg composites decompose in three degradation stages. NaAlg impairs the thermal stability of all composites and no difference was found between the influence of different molecular weights and the preparation processes.

Modifikacija svojstava poli(etilen-oksida) (PEO) provedena je dodatkom natrijevog alginata (NaAlg) s ciljem urušavanja njegove kristalnosti i poboljšavanja vodljivosti. Uspješno su pripravljeni filmovi svih mješavina izlijevanjem iz otopine. Primjenom infracrvene spektroskopije s Fouierovom transformacijom (FT-IR) potvrđena je interakcija između PEO-a i NaAlg-a u vidu vodikovih veza. Diferencijalna pretražna kalorimetrija (DSC) je primijenjena u istraživanju utjecaja natrijevog alginata na toplinska svojstva i kristalnost PEO-a. Dodatak biorazgradljivog NaAlg-a, različita molekulna masa PEO-a i različita koncentracija početnih polimernih otopina složeno djeluje na toplinska svojstva PEO-a uz smanjivanje njegove kristalnosti kod pojedinih filmova polimernih mješavina. Toplinska postojanost mješavina istraživana je primjenom neizotermne termogravimetrije (TG). Polimerne mješavine PEO/NaAlg razgrađuju se u tri stupnja razgradnje. NaAlg pogoršava toplinsku postojanost filmova polimernih mješavina. Zaostala voda uslijed nedovoljnog sušenja filmova utječe na sva ispitivana stvojstva pripravljenog polimernog materijala što navodi na potrebu modificiranja postupka priprave filmova. The modification of properties of poly (ethylene oxide) (PEO) was performed by adding sodium alginate (NaAlg) with the aim of reducing its crystallinity and improving its conductivity. Films of all blends were successfully prepared by solution casting method. By applying Fourier transform infrared spectroscopy (FT-IR) the interaction between PEO and NaAlg was confirmed in the form of hydrogen bonds. Differential scanning calorimetry (DSC) has been applied to investigate the influence of sodium alginate on the thermal properties and crystallinity of PEO. The addition of biodegradable NaAlg, different molecular weight of PEO and different concentration of starting polymer solutions have a complex effect on the thermal properties of PEO while reducing its crystallinity in some polymer blend films. The thermal stability of blends was investigated using non-isothermal thermogravimetry (TG). PEO/NaAlg polymer blends degrades throught three degradation steps. NaAlg impairs the thermal stability of polymer blend films. Due to insufficient film drying, residual water affects all the tested properties of the prepared polymer material, which leads to future modification of the film preparation.

Nove tehnologije pakiranja razvijaju se kao odgovor na zahtjeve potrošača i trendove industrijske proizvodnje prema dobro čuvanim, svježim, ukusnim i praktičnim proizvodima s produljenim rokom trajanja i kontroliranom kvalitetom. Kako bi se produljio rok trajanja bilo koje vrste pakirane hrane, potrebno je kontinuirano razvijati svojstva ambalažnih materijala. Nanotehnologija je pokazala mnoge prednosti u različitim područjima pa tako i u području industrije ambalaže prehrambenih proizvoda. Zahtjevi za odgovarajuću propusnost polimernih materijala prema plinovima i parama, dobre barijere i mehanička svojstva polimera, te nekim naprednim svojstvima ambalaže pojačali su interes za razvoj novih tehnologija. Razvoj polimernih materijala u kombinaciji s odgovarajućom nanopunilima, te novi načini formuliranja nanokompozita imaju veliki potencijal kod primjene u različitim vrstama pakiranja. Upotreba nanokompozita u pakiranju hrane može predstavljati rizik za potrošače zbog čestica koje mogu migrirati iz nanomaterijala u proizvod. Stoga je nužna provjera opsega migracija nanočestica iz ambalaže u hranu i razvoj metoda za sprečavanje takvih migracija. New packaging technologies are developed as response to consumer demands and industrial production trends to well-preserved, fresh, delicious and practical products with extended durability and controlled quality. In order to extend the shelf life of any type of packaged food, it is necessary to continually develop the properties of packaging materials. Nanotechnology has shown many advantages in various areas, including in the field of food packaging industry. Requirements for the appropriate gaseous and vapor-proof polymer material, good barrier and mechanical properties of the polymer and some advanced packaging properties have intensified interest in the development of new technologies. The development of polymeric materials in combination with appropriate nanfillers and new forms of nanocomposite formulation, have great potential in the application of different types of packaging. The use of nanocomposites in food packaging can pose a risk to consumers due to particulate matter that can migrate from nanomaterials to the product. It is therefore necessary to check the scope of migration of nanoparticles from food packaging and the development of methods to prevent such migration.

Termoplastični poliuretan (TPU) je vrlo poželjan materijal za medicinsku primjenu zbog njegove fleksibilnosti, trajnosti i otpornosti na ulja i kemikalije. S druge strane, fibroin svile je jedinstveni i obećavajući prirodni materijal dobiven iz dudovog svilca te zbog svoje biokompatibilnosti, biorazgradivosti i netoksičnosti ima veliki potencijal za primjenu kao biomedicinski materijal. Cilj ovoga rada bio je pripremiti i karakterizirati fizikalna, toplinska i mehanička svojstva mješavina sastavljenih od elastičnog termoplastičnog poliuretana (TPU) u koji je umješan različiti udio fibroina svile (FS). TPU/FS mješavine pripremljene su dodatkom 5%, 10%, 15% i 20 mas% FS umješavanjem u laboratorijskoj Brabender gnjetilici. Uzorci čistih komponenti i mješavina dobiveni su prešanjem na hidrauličkoj preši. Određena je struktura, toplinska i mehanička svojstva čistih komponenata (TPU i FS) i njihovih mješavina (TPU/FS) primjenom infracrvene spektroskopije s Fourierovim transformacijama (FT-IR) i prigušene totalne refleksije (ATR), diferencijalnom pretražnom kalorimetrijom (DSC) i termogravimetrijskom analizom (TGA). Mehanička svojstva čistih komponenata i mješavina određena su testom rasteznog naprezanja upotrebom mehaničke kidalice. Dobiveni rezultati FTIR analize pokazuju da je fibroin svile ugrađen u TPU matricu. Rezultati dobiveni DSC tehnikom pokazali su da se dodatkom fibroina svile temperatura staklastog prijelaza povećava, dok se talište smanjuje, zbog nastajanja slabije uređene kristalne strukture nastale dodatkom fibroina svile. Toplinska stabilnost određena je termogravimetrijskom analizom iz koje se vidi da se dodatkom fibroina svile smanjuje toplinska stabilnost TPU/FS mješavina. Povećanjem udjela fibroina svile prekidna čvrstoća i prekidno istezanje se smanjuju. Thermoplastic polyurethane (TPU) is very desirable for medical applications because of its flexibility , durability, and resistance against oils and chemicals. Silk fibroin (SF), a unique and promising natural material extracted from silkworm, has gained much attention for its use as biomedical material, because of its biocompatibility, biodegradability and nontoxicity. The aim of this work was to preparation and characterization the mechanical, physical and thermal properties of blends containing a highly elastic thermoplastic polyurethane (TPU) compounded with different silk contents. TPU/SF blends were prepared with melt mixing of TPU with 5%, 10%, 15% i 20 wt% of SF in a laboratory Brabender mixer. The specimenes of the neat components and their blends were molded in hydraulic press. The structural characteristics, thermal and mechanical properties of the neat TPU, SF and their blends (TPU/SF) were examined by Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Mechanical properties of the neat components and their blends were determined by a tensile test using universal testing machine. The FTIR results showed that the silk fibroin was successfully introduced to TPU scaffolds. Results obtained with DSC showed that with addition of silk fibroin, glass transition temperature increases, while melting temperature and degree of crystallinity decreases, because of the less organized crystal structure with addition of silk fibroin. Thermal stability is determined by TGA which shows that with addition of silk fibroin thermal stability decreased. With increasing SF content, the tensile strength and elongation at break decreased.

Polimerne mješavine su višefazni sustavi, tj. fizikalne smjese dvaju ili više polimera. Svojstva mješavina ovise o svojstvima pojedinog konstituenta, njihovoj morfologiji i adheziji na međupovršini između faza. Cilj ovog istraživanja bio je ispitati utjecaj otpadnog praha poliamida 12 (PA 12) i polilaktida (PLA) na toplinska i mehanička svojstva te svojstva međupovršine PA12/PLA. Toplinska, mehanička i površinska svojstva istražena su za ishodne polimere: PA12 i PLA te za PA12/PLA mješavine različitog sastava koje su pripravljene u Brabender gnjetilici. Toplinska svojstva ispitana su pomoću diferencijalne pretražne kalorimetrije (DSC) i termogravimetrijske analize (TGA), dok su mehanička svojstva ispitana rasteznim testom. Metoda kontaktnog kuta korištena je za ispitivanje površinskih svojstava. Dobiveni rezultati ukazuju na porast toplinske stabilnosti PLA dodatkom otpadnog praha PA12 i značajan utjecaj na kristalnost PLA polimera. Sniženje prekidne čvrstoće uz sniženje prekidnog istezanja ukazuje na slabu adheziju između PA12 i PLA polimera. Dobivene vrijednosti parametara adhezije u skladu su s rezultatima mehaničkih svojstava. The polymer blends are multiphase systems i.e. physical mixtures of two or more polymers. Properties of blends depend on the properties of their individual constituents, their morphology and interfacial adhesion between phases. The aim of this study was to investigate the impact of polyamide 12 (PA 12) and polylactide (PLA) on thermal and mechanical properties and PA12/PLA surface properties. Thermal, mechanical and surface properties were investigated for the starting polymers: PA12 and PLA and for the PA12/PLA blends of the different composition prepared in the Brabender kneader. Thermal properties were tested by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), while the mechanical properties were tested by a stretch test. The contact angle method was used to investigate surface properties. The obtained results indicate an increase in thermal stability of PLA by the addition of PA12 waste powder and a significant influence on the PLA crystallinity. The lowering tensile strength with the lowering elongation at break indicates poor adhesion between PA12 and PLA polymers. The obtained values of the adhesion parameters are consistent with the results of the mechanical properties.

U ovom radu ispitan je utjecaj dodatka TiO2 nanočestica u rasponu masenih udjela od 1 do 5% na strukturu i svojstva polimerne poliamidne PA 2200 matrice. Polimerni nanokompoziti pripravljeni su postupkom iz taline koristeći Brabender gnjetilicu te hidrauličku prešu Fontune. Karakterizacija uzoraka provedena je diferencijalnom pretražnom kalorimetrijom (DSC), termogravimetrijskom analizom (TGA), metodom istoosnog istezanja te je određena toplinska vodljivost THB metodom. DSC analiza pokazuje kako TiO2 nanopunila poboljšavaju kristalizaciju polimerne matrice, povisuju temperature kristalizacije polimerne matrice odnosno djeluju kao nukleacijski centri. TiO2 punila također pospješuju stvaranje stabilnijih i uređenijih kristalnih struktura. TGA analizom dokazano je da dodatak TiO2 nanopunila povećava temperaturu početka razgradnje PA matrice odnosno poboljšava toplinsko stabilnost PA matrice. Ispitivanjem mehaničkih svojstava uzoraka istoosnim istezanjem vidljivo je kako dodatkom nanopunila dolazi do smanjenja modula te neznatnih promjena čvrstoće i istezanja u točki popuštanja u odnosu na čistu polimernu matricu. Dodatak TiO2 nanočestica povećava vrijednosti toplinske vodljivosti nanokompozita u odnosu na čistu polimernu matricu. In this paper, the effect of the addition of TiO2 nanoparticles of a range of 1% wt. to 5% wt. on the structure and properties of PA 2200 polymer matrix was investigated. Polymer nanocomposites were prepared by melting the polymer and mixing the nanoparticles using the Brabender plasticoder and Fontune hydraulic press. The characterization of the samples was performed using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tenisle test and thermal conductivity using THB method. DSC analysis shows that TiO2 nanofiller improve the polymer matrix crystallization and increase the crystallization temperature of the polymer matrix by acting as nucleation centres. Additionally, TiO2 nanofiller contribute to the formation of more stable crystal structures. TGA analysis showed that addition of TiO2 nanoparticles shifts the temperature at the beginning of degradation toward higher values, therefore increasing thermal stability of PA matrix. Mechanical properties determined by tensile stress test, imply that by the addition of the TiO2 nanofiller, the secant modulus is reduced. Additionally, slight changes in yield stress and yield strain relative to the pure polymer matrix were observed. The addition of TiO2 nanoparticles increases the thermal conductivity of a nanocomposite relative to a pure polymer matrix.

U današnje vrijeme, napretkom tehnologije došlo je razvoja 3D pisača koji omogućuju tiskanje objekata bez naknadne obrade. Materijal koji se najčešće koristi za 3D tiskanje je prah poliamida 12 (PA 12). Cilj ovog rada bio je ispitati utjecaj SLS procesa na strukturu i svojstva PA 12. Analizirane su tri generacije PA 12 praha: uzorci novog praha, uzorci praha koji je dva puta prošao ciklus SLS procesa te uzorak otpadnog praha. Nadalje uzorci prahova su pretaljeni u Brabenderu kako bi se istražila moguća daljnja upotreba otpadnog praha. Toplinska svojstva uzoraka ispitana su diferencijalnom pretražnom kalorimetrijom (DSC), a toplinska stabilnost termogravimetrijskom analizom (TGA). Mehanička svojstva određena su testom jednoosnog istezanja, a raspodjela veličina čestica ispitivanih uzoraka laserskom difrakcijom. Rezultati DSC analize pokazali su da povećanjem broja korištenja praha dolazi do smanjenja uređenosti kristalne strukture što je posljedica taljenja jednog dijela kristalnih lamela uslijed visokih temperatura u SLS procesu. Također, pretaljivanjem se djelomično gubi uređenost kristalne strukture i znatno smanjuje udio kristalne faze u uzorku. TGA analiza ukazuje na smanjenje početne toplinske stabilnosti, a povećanje stabilnosti na kraju razgradnje ispitivanih uzoraka praha što je PA prah prošao više ciklusa 3D tiskanja. Isti trend je zabilježen i kod pretaljenih uzoraka. Testom jednoosnog istezanja nisu zabilježene značajnije promjene u vrijednostima naprezanja i istezanja u točki popuštanja, ali se s povećanjem broja ciklusa SLS-a vrijednosti sekantnog modula povećavaju. Rasipanje vrijednosti prekidnog naprezanja i istezanja predstavljaju ozbiljno ograničenje korištenja otpadnog praha za druge primjene. Nowadays, advancement in techonoly brought development of 3D printers which allows printing the object without additional processing. Material which is used the most in 3D printing is powder of Polyamide 12 (PA 12). Purpose of this work is to examine influence of SLS process on structure and properties of PA 12 powder. Three generations of PA 12 powder were analyzed: samples of virgin powder, samples which were used two times in SLS process and samples of waste powder. Furthermore, powder samples were pre-melted in Brabender to investigate the possible further use of waste powder. Thermal properties of samples were determined by differential scanning calorimetry (DSC), and thermal stability by thermogravimetric analysis (TGA). Mechanical properties were determined by tensile test and particle size distribution of powder by laser diffraction. The results of the DSC analysis showed that by increasing the number of SLS cycles, the arrangement of the crystal structure in powder decreases, which is a consequence of the melting of one part of the crystal lamellae due to the high temperatures in the SLS process. Also, with melting there is partial lost of the crystalline structure arrangement and significant reduction in degree of crystallinity. TGA analysis showed decreasing in initial thermal stability, but increasing stability at the end of degradation for examined powder samples as PA powder has undergone multiple cycle of 3D printing. Same trend is also in samples which were pre-melted. Tensile test indicated that there was not significant changes of strain and elongation in yield point, but with increasing number of SLS cycles of process there is increase of secant modulus. Dissipation of values for strain and elongation at break presents major limit for using waste powder in for further applications.

Rad se bavi problemom otpornosti materijala zidanih konstrukcija te ziđa na cikluse smrzavanja i odmrzavanja. Istražen je utjecaj režima pečenja opeka na njihovu otpornost na cikluse smrzavanja i odmrzavanja te je zaključeno kako duži period zadržavanja opeka u peći na najvišoj postignutoj temperaturi rezultira boljom otpornošću opeka na cikluse smrzavanja i odmrzavanja te kako način izrade opeke i režim njezina pečenja utječu na sustav pora koji će se razviti u opeci tako da sličan sustav pora razvijaju opeke izrađene na isti način. Na 16 serija opeka su određeni sljedeći parametri: tlačne čvrstoće opeka prije i nakon izlaganja ciklusima smrzavanja i odmrzavanja te njihovi omjeri, koeficijent zasićenja, specifična površina BET metodom, udio pora pojedine veličine te ukupni udio pora, ukupni volumen pora i srednji radijus pora pomoću živinog porozimetra, ukupni udio pora hidrostatskim vaganjem, Maage koeficijent, koeficijent početnoga upijanja, vodoupojnost te je praćeno upijanje i otpuštanje vode kod opeka u vremenu od 24 h. Temeljem niza pobrojanih parametara matematičkim putem provjerena je mogućnost ovih parametara da klasificiraju opeku na otpornu i neotpornu na cikluse smrzavanja i odmrzavanja te potražen matematički model koji opisuje omjer tlačnih čvrstoća opeka nakon i prije izlaganja ciklusima smrzavanja i odmrzavanja. Zaključeno je da su vodoupojnost i koeficijent otpuštanja vode iz opeke u vremenu 180-360 minuta izvrsni klasifikatori za klasifikaciju opeke na otporne i neotporne. Za odabrane opeke provedena je nanotomografija kojom se dobio uvid u udio otvorenih i zatvorenih pora u opeci te je uočeno kako opeke s većim udjelom otvorenih pora u ukupnom udjelu pora imaju veći omjer tlačnih čvrstoća nakon i prije smrzavanja, a time i bolju otpornost na cikluse smrzavanja i odmrzavanja. Ovo u nastavku znači da osim distribucije pora bitnu ulogu kod otpornosti opeke na cikluse smrzavanja i odmrzavanja ima i vrsta pora. U nastavku je istražen utjecaj ciklusa smrzavanja i odmrzavanja na mortove različitih sastava; vapnene, produžne, cementne i cementne s dodatkom aeranta u kojima su volumno varirani omjeri komponenata unutar pojedine skupine. Najbolju otpornost u kontekstu omjera čvrstoća nakon i prije ciklusa smrzavanja i odmrzavanja pokazali su cementni mortovi sa aerantom, potom cementni mortovi dok su se uzorci vapnenog i produžnog morta raspali prilikom izlaganja ciklusima smrzavanja i odmrzavanja te im nije bilo moguće odrediti otpornost. Odabranom cementnom mortu te dvjema serijama opeka određena su toplinska svojstva prije i nakon izlaganja ciklusima smrzavanja i odmrzavanja te je uočeno da ciklusi smrzavanja i odmrzavanja negativno utječu na toplinsku provodljivost te da ona raste nakon izlaganja uzoraka tom djelovanju što znači da materijali nakon ciklusa smrzavanja i odmrzavanja osim na mehaničkim svojstvima gube i na svojstvu toplinske izolacije. Napravljeno je ziđe od odabranih opeka i odabranoga morta kojem je ispitivanjem određena početna posmična čvrstoća prije i nakon smrzavanja te računski određen koeficijent prolaska topline prije i nakon smrzavanja te isti stavljeni u omjer. Zaključeno je da ciklusi smrzavanja i odmrzavanja slabe kako mehanička tako i toplinska svojstva ziđa što u nastavku znači veću potrošnju energije i veće troškove grijanja u objektima te veću godišnju emisiju CO2. Ovo ukazuje na potrebu za bržom i cijenom pristupačnijom metodom za ocjenu otpornosti opeke, kao većinskoga dijela zidanih građevina, na cikluse smrzavanja i odmrzavanja te se temeljem u radu provedenog istraživanja kao odabrana metoda preporučuje ispitivanje vodoupojnosti. Ispitivanje vodoupojnosti je jednostavna metoda kojom bi i sami proizvođači opečnih zidnih elemenata mogli provjeriti otpornost opeke na cikluse smrzavanja i odmrzavanja u okviru kontrole tvorničke proizvodnje., The paper deals with durability of materials in wall structures and masonry with respect to freeze and thaw cycles. It also examines the effect of the selected brick firing regime on the resistance of bricks to freeze and thaw cycles. Results of the examination lead to the conclusion that the longer a brick is fired in the kiln at a maximum achieved temperature, the better is its resistance to freeze and thaw cycles. Another conclusion is that the brickmaking method and its firing regime also affect the pore system developed and that the pore system will be more similar in bricks made using the same method. The following parameters were determined based on 16 batches of bricks: compressive strength of bricks before and after exposure to freeze and thaw cycles and ratios of measured values; saturation coefficient; specific surface area determined by applying the BET method; portion of pores of particular sizes and total portion of pores; total pore volume and average pore radius measured by a mercury porosimeter; total portion of pores measured based on hydrostatic weighing; Maage’s index; initial absorption coefficient and water absorption. In addition, water absorption and desorption of bricks was monitored through a 24-hour period. Based on said parameters, the possibility of their use for the purposes of classifying bricks as resistant or non-resistant to freeze and thaw cycles was mathematically calculated. In addition, a mathematical model describing the ratio of compressive strength values of bricks, measured before and after exposure to freeze and thaw cycles, was also sought. It was concluded that water absorption and the water desorption coefficient of bricks, measured for a period of 180-360 minutes, are excellent classifiers for classification of bricks as resistant or non-resistant. Nanotomography was performed on selected bricks to gain an insight into the portion of open and closed pores in bricks. It was determined that bricks with a higher portion of open pores relative to the total portion of pores have a higher ratio of compressive strength values measured after and before the freezing cycle and are, therefore, more resistant to freeze and thaw cycles. What that indicates is that, in addition to pore distribution, the type of pore also plays a significant role in the resistance of bricks to freeze and thaw cycles. Furthermore, the paper examined the effect of freeze and thaw cycles on different types of mortars: lime; lime-based; cementitious; and cementitious mortar with added air-entraining agent. Ratio of the volume of components in said types of mortars was varied for each individual group. The highest resistance, in terms of compressive strength ratio of values measured before and after the freeze and thaw cycle, was measured in cementitious mortars with added air-entraining agent. They were followed by cementitious mortars, while the lime and lime-based mortar samples decomposed during exposure to freeze and thaw cycles, thus making their resistance impossible to determine. Thermal characteristics of the selected cementitious mortar and of two batches of bricks were determined before and after exposure to freeze and thaw cycles. It was observed that freeze and thaw cycles have a negative effect on thermal conductivity and that it increases after the samples are exposed to such processes. This means that both the mechanical and thermal insulation characteristics decrease after the materials are exposed to freeze and thaw cycles. Masonry was constructed by using selected bricks and mortar and, through tests, its initial shear strength was measured before and after exposure to the freeze cycle. In addition, the heat transfer coefficient was calculated before and after the freeze cycle, after which a comparison of these two values was made and their mutual ratio determined. The conclusion was that freeze and thaw cycles diminish both the mechanical and thermal characteristics of masonry, which, in turn, leads to greater energy consumption and higher heating costs in buildings, as well as higher annual CO2 emissions. This points to the need for a faster and more economical method of evaluating the resistance of bricks to freeze and thaw cycles, because masonry structures are, for the most part, constructed from bricks. Based on the research conducted for the purpose of this paper, the recommended method is water absorption testing. Water absorption testing is a simple method which could be used by manufacturers of clay masonry units within their production quality control in the factory to verify the resistance of bricks to freeze and thaw cycles.

U ovom radu ispitana su toplinska svojstva mješavina različitog udjela polilaktida (PLA) i termoplastičnog škroba (TPS). TPS je pripremljen s različitim udjelima glicerola (30 i 40 mas. %) kao plastifikatora. Radi uvida u hidrofilni/hidrofobni karakter mješavina PLA/TPS praćena je apsorpcija vode. Rezultati toplinskih svojstava pokazali su da TPS ubrzava proces hladne kristalizacije polilaktida uslijed nukleacijskog učinka TPS-a. TPS povećava sposobnost kristalizacije PLA i omogućava pravilnije slaganje lanaca polilaktida u kristalnoj strukturi. Utjecaj glicerola kao plastifikatora TPS-a nema značajnu ulogu u ispitivanju toplinskih svojstava, dok je ispitivanje apsorpcije vode pokazalo da se uz veći udio glicerola kao plastifikatora TPS-a dobivaju niže vrijednosti apsorpcije vode mješavina PLA/TPS. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna., In this paper, thermal properties of polylactide (PLA) and thermoplastic starch (TPS) blends with different proportions of TPS were investigated. TPS at different ratios of glycerol (30 and 40 wt. %) as a plasticizer, were prepared. To gain an insight into the hydrophilic/hydrophobic character of the PLA/TPS blends, water absorption was performed. The results of thermal properties indicated that TPS enhanced the cold crystallization process of polylactide due to the nucleation effect of TPS. TPS increases the ability of the PLA crystallization and provides a more accurate alignment of polylactide chains in the crystal structure. The effect of glycerol as a TPS plasticizer has no significant role in the thermal properties, while water absorption testing has shown that with higher glycerol content as TPS plasticizers, lower water absorption values of PLA/TPS blend are obtained. This work is licensed under a Creative Commons Attribution 4.0 International License.

Polimerni nanokompoziti područje su brojnih istraživanja zbog svojih poboljšanih svojstava u odnosu na klasične polimerne materijale i kompozite što im omogućuje široku primjenu. Takva svojstva im omogućuju nanopunila koja zbog svojih dimenzija i strukture sama posjeduju izvanredna svojstva. U ovom radu provedena su istraživanja utjecaja dodatka ugljikovih nanocjevčica (MWCNT) i modificiranih ugljikovih nanocjevčica (MWCNT-COOH) masenih udjela u rasponu od 0,5 % do 5 % u poliamidnu matricu (PA). Uzorci PA i nanokompozita pripremljeni su postupkom iz taline. Zamiješani su u Brabender gnjetilici te potom prešani na laboratorijskoj hidrauličkoj preši. U svrhu analize toplinskih, mehaničkih i električnih svojstava PA/MWCNT i PA/MWCNT-COOH nanokompozita, provedena je karakterizacija uzoraka diferencijalnom pretražnom kalorimetrijom (DSC), termogravimetrijskom analizom (TGA), THB metodom određivanja toplinske vodljivosti, testom jednoosnom istezanja te elektrokemijskom impedancijskom spektroskopijom (EIS). Rezultati DSC analize pokazali su da ugljikove nanocjevčice (MWCNT) djeluju kao nukleacijski centri i ubrzavaju kristalizaciju PA matrice, ali ne utječu na uređenost kristalne strukture. Zbog polarne prirode površine i bolje dispergiranosti, MWCNT-COOH punila znatnije ubrzavaju kristalizaciju PA u odnosu na MWCNT. Iako ugljikove nanocjevčice imaju nukleacijski učinak, zbog njihove prisutnosti lanci PA imaju ograničen prostor za gibanje što ometa proces kristalizacije matrice. Toplinska stabilnost PA matrice se povećava dodatkom oba punila MWCNT i MWCNT-COOH te se početak razgradnje pomiče na više temperature. Veća se toplinska vodljivost postiže dodatkom punila MWCNT-COOH u odnosu na dodatak MWCNT. Ovakvi rezultati pripisuju se dobroj toplinskoj vodljivost MWCNT. Rezultati testa jednoosnog istezanja su pokazali da se dodatkom obje vrste MWCNT punila u PA matricu, smanjuje modul elastičnosti i čvrstoća u točki popuštanja te se povećava istezanje u točki popuštanja. Ovakvo ponašanje može se pripisati učinku MWCNT punila koje djeluje na PA tako što smanjuje udio matrice koji može kristalizirati što utječe na smanjenje modula i čvrstoće te povećanje deformabilosti nanokompozitnih sustava. Rezultati ispitivanja električne vodljivosti nanokompozita EIS metodom pokazuju jednake vrijednosti impendacije (otpora) kao i čista PA matrica. Polymer nanocomposites are a field of numerous researches due to their improved properties compared to conventional polymeric materials and composites which enables them to be widely used. Nanofillers possesses remarkable properties because of their dimensions and structure which enabels them improve the properties of the nanocomosites. In this study the addition of carbon nanotubes (MWCNT) and modified carbon nanotubes (MWCNT-COOH) in the range of 0.5 wt. % to 5 wt. % in the polyamide matrix (PA) was investigated. PA and nanocomposite samples were prepared by melt mixing in a Brabender plasticoder and then pressed on a laboratory hydraulic press. For the purpose of analyzing the thermal, mechanical and electrical properties of PA/MWCNT and PA/MWCNT-COOH nanocomposites, the samples were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), THB thermal conductivity determination method, tensile test and electrochemical impedance spectroscopy (EIS). Results of DSC analysis showed that carbon nanotubes (MWCNTs) act as nucleation centers and accelerate the crystallization of PA matrix, but do not affect the order of the crystal structure. Due to the polar nature of the surface and the better dispersion, MWCNT-COOH fillers more significantly accelerate the PA crystallization compared to MWCNT. Although the carbon nanotubes have a nucleation effect, due to their presence the PA chains have limited motion space which interferes with the crystallization process of the matrix. The thermal stability of the PA matrix increases with the addition of both MWCNT and MWCNTCOOH fillers, and the start of decomposition moves to higher temperatures. The higher thermal conductivity is achieved by the addition of MWCNT-COOH filler compared to the addition of MWCNT. Such results are attributed to the good thermal conductivity of MWCNT. The results of the tensile test showed that by adding both types of MWCNT fillers in the PA matrix, the modulus of elasticity and the yield stress are reduced, but the yield strain increases. This behavior can be attributed to the effect of MWCNT fillers on PA which reduces the fraction of the matrix that can crystallize, which then affects the reduction of the modulus and yield strength and increases the deformability of the nanocomposite systems. The results of the EIS method of the electrical conductivity of the nanocomposites show equal impendance (resistance) as the pure PA matrix.

Voskovi su sve krute ili tekuće tvari koje sadrže ugljikovodike, kiseline, alkohole i estere bez obzira na podrijetlo ili način dobivanja. Zbog njihove složene strukture nije ih jednostavno opisati i zato postoje razne podjele voskova. Prema podrijetlu dijele se na prirodne i sintetske. Prirodni voskovi su materijali biljnog ili životinjskog podrijetla a dobivaju se iz različitih sjemenki, povrća, izlučevina pčela i drugih insekata. Svojstva tih materijala razlikuju se od svojstava sintetskih voskova koji se dobivaju iz nafte, minerala i produkata nafte. Dobro su poznati prirodni voskovi karnaube, soje, montana, šelak i pčelinji vosak ali njihova količina je znatno manja u usporedbi sa sintetskim voskovima koji se dobivaju iz nafte. U ovom radu istražena su svojstva šest voskova, tri prirodna i tri sintetska. Strukturna analiza voskova provedena je primjenom FTIR-ATR spektroskopije a površinske karakteristike mjerenjem kontaktnog kuta. Toplinska svojstva voskova analizirana su pomoću diferencijalnog pretražnog kalorimetra. Analiza gorenja provedena je na svijećama pripravljenim od različitih voskova te je procijenjena brzina gorenja. Waxes are all solids and liquids found in nature, and to those that occur individually in waxes, such as the hydrocarbons, acids, alcohols, and esters irrespective of their source or method of preparation, provided such couslituents are waxlike in their properties. Because of their complex structure, it is not easy to describe them and because of this there is different waxes classification. By the origin, they are divided into natural and synthetic. Natural waxes are materials made from plant and animals derived from vegetables, beans, bees and other insects. Natural waxes have properties different from synthetic waxes derived from crude oil, mineral or petroleum products. Well known natural waxes are carnauba, soya, montan, beeswax, schelak, but their quantity is very small compared to crude oil and synthetic waxes. Paraffin is synthetic wax a mixture of aliphatic or saturated hydrocarbons recovered from crude oil by distillation. In this study properties of six waxes are investigated, three from natural sourceand three synthetic. Structural analysis of waxes were performed by using FTIR-ATR spectroscopy and surface characteristics by using contact angle measurement. Thermal properties of waxes were analyzed by using differential scanning calorimetry (DSC). Analysis of burning were performed on the candles prepared from different waxes and velocity of wax burning is estimated.

Cilj ovoga rada bio je pripremiti i karakterizirati LDPE/PCL mješavine u različitim omjerima te odrediti utjecaj vremena UV razgradnje na svojstva mješavina. Karakterizacija LDPE/PCL mješavina napravljena je s naglaskom na toplinska svojstva mješavina. Mješavine polietilena niske gustoće (LDPE) i polikaprolaktona (PCL) pripravljene su u različitim omjerima: 100/0, 90/10, 70/30, 50/50, 30/70, 10/90 i 0/100 mas %. LDPE/PCL mješavine pripravljene su umješavanjem u laboratorijskoj gnjetilici Brabender. Uzorci čistih polimera i mješavina dobiveni su prešanjem na hidrauličkoj preši. Uzorci čistih LDPE i PCL te LDPE/PCL mješavina u različitim omjerima bili su izloženi UV zračenju deset, dvadeset i trideset dana. Karakterizacija toplinskih svojstava LDPE/PCL mješavina provedena je tehnikom termogravimetrijske analize (TGA). Struktura mješavina prije izlaganja UV zračenju te nakon deset i trideset dana zračenja određena je kombiniranom tehnikom infracrvene spektroskopije s Fourierovim transformacijama (FT-IR) i prigušene totalne refleksije (ATR). Toplinska stabilnost mješavina smanjuje se povećanjem udjela PCL. To se da zaključiti iz činjenice da se temperatura početka razgradnje pomiče prema nižim temperaturama dodatkom PCL. The aim of this work was to preparation and characterization of LDPE/PCL blends under different LDPE/PCL content and to determine the effect of UV degradation time on the properties of the blends. The characterization of LDPE/PCL blends was made under accent on thermal properties. Blends of low density polyethylene and polycaprolactone were made in different LDPE/PCL content: 100/0, 90/10, 70/30, 50/50, 30/70, 10/90 and 0/100 wt %. LDPE/PCL blends were prepared with melt mixing in laboratory Brabender mixer. The specimens of neat polymers and LDPE/PCL blends were molded in hydraulic press. The specimens of neat polymers and LDPE/PCL blends were exposed to UV irradiation for 10 and 30 days. The thermal properties of neat LDPE, neat PCL and LDPE/PCL blends were investigated by thermogravimetric analysis (TGA). The changes in the structure of the blends were investigated before exposure to UV irradiation and after 10 and 30 days of UV exposure time by combined technique of Fourier Infrared Spectroscopy (FT-IR) and Attenuated Total Reflection (ATR). The thermal stability of the blends decreases with increase of the PCL content. That can be concluded from the fact that the temperature of beginning of degradation is shifted to lower temperatures by the increase of PCL content.

Polimerni nanokompoziti su kompoziti kod kojih se barem jedna faza nalazi u nanodimenzijama. Različiti polimeri kao što su termoplasti i elastomeri mogu se koristiti za proizvodnju polimernih nanokompozita. Nanopunila mogu poboljšati mehanička svojstva samih polimernih materijala ako su manjih dimenzija od 100 nm. Tema istraživanja ovog rada je utjecaj višestjenih ugljikovih nanocjevčica (multiwalled carbon nanotubes - MWCNT) na toplinska svojstva, proces kristalizacije, mehanička svojstva te na morfologiju čistog polikaprolaktona (PCL) i nanokompozita (PCL/CNT) s različitim udjelom nanocjevčica. Nanokompoziti PCL/CNT dobiveni su na dva načina, umješavanjem MWCNT u taljevinu PCL-a u Brabender gnjetilici i dodavanjem MWCNT u otopinu PCL-a i tetrahidrofurana (THF). Toplinska karakterizacija materijala provedena je tehnikama toplinske analize: diferencijalnom pretražnom kalorimetrijom (DSC); dinamičko mehaničkom analizom (DMA). Mehanička svojstva ispitana su na mehaničkoj kidalici, a morfologija PCL i PCL/CNT nanokompozita snimljena je pretražnim elektronskim mikroskopom (SEM). Dobiveni rezultati pokazali su da je bolji način pripreme nanokompozita PCL/CNT u Brabender gnjetilici u odnosu na otopinu PCL/THF. Polymer nanocomposites are composites in which at least one phase is expressed in nanometers. Different polymers such as thermoplastic and elastomers can be used for polymer nanocomposites preparation. Nanofillers can improve mehanical properties of polymer materials if they are smaller than 100nm. The aim of this study is the influence of multiwalled carbon nanotubes (MWCNT) on thermal properties, crystallization process, mehanical properties and morphology of polycaprolactone (PCL) and nanocomposites (PCL/CNT) with different weight ratios of MWCNT. PCL/CNT nano-composites were obtained in two ways, first one was by mixing MWCNT in PCL melt in Brabender mixer and the second one was dissolving PCL in tetrahydrofuran (THF) and than adding MWCNT to solution. Thermal characterization was obtained by thermal analysis: differential scanning calorimetry (DSC); dynamic mechanical analysis (DMA). Mehanical properties were determined with universal testing machine. The morphology of PCL and PCL/CNT nanocomposites was recorded by scanning electron microscopy (SEM). The obtained results were compared and showed that a better way of preparing PCL/CNT nanocomposites is in Brabender mixer than dissolving PCL in THF.

Cilj ovoga rada bio je ispitati svojstva čistih komponenata polilaktida (PLA-S, PLA-N), polietilena visoke gustoće (PE-HD) i polietilena niske gustoće (PE-LD). Također, su ispitana svojstva pripremljenih polimernih mješavina PLA-S/PE-HD, PLA-S/PE-LD, PLA-N/PE-HD i PLA-N/PE-LD 95/5 i 90/10 bez i uz dodatak punila (TiO2, silika). Uzorci su umješavani u Brabender gnjetilici. Određena su mehanička i toplinska svojstva čistih komponenata i pripremljenih polimernih mješavina. Također, je ispitana morfologija na temelju mehaničkih svojstava odabranih uzoraka. Snimljeni su FTIR spektri čistih komponenata. Na temelju dobivenih rezultata zaključeno je da polimerne mješavine bez dodatka punila imaju manju prekidnu čvrstoću i rad loma u odnosu na čiste komponente. U mješavinama PLA-N kao bolje punilo se pokazao TiO2, dok je u mješavinama s PLA-S kao bolje punilo odabrana silika. Proučavanjem morfologija mješavina, zaključeno je da najveći utjecaj na mehanička svojstva ima raspodjela veličina čestica i dispergiranost faza. The aim of this study was to determine the properties of 95/5 and 90/10 PLA-S/PE-HD, PLA-S/PE-LD, PLA-N/PE-HD and PLA-N/PE-LD polymer mixtures prepared without and with filler addition (TiO2, silica). Also, properties of pure polylactide (PLA-S, PLA-N), high density polyethylene (PE-HD) and low-density polyethylene (PE-LD) have been tested. Samples were blended in the Brabender mixer. Mechanical and thermal properties of pure components and prepared polymer blends were obtained. The morphology of selected samples was tested. FTIR spectra of pure components were recorded. Based on the obtained results, it was concluded that the polymer blends without the addition of filler have lower strength at break than the pure component. In PLA-N blends, TiO2 has been shown, as a better filler, while in PLA-S blends silica was a better choice. Morphology studies showed that particle size distribution and phase dispersion have the greatest influence on the mechanical properties of the blends.

U ovom radu istraživan je učinak dodatka višestjenih ugljikovih nanocjevčica (MWCNT) te MWCNT-a modificiranog skupinama COOH (MWCNT-COOH) u rasponu masenih udjela od 0 do 4 % na svojstva termoplastičnog poliuretana (PU). Uzorci nanokompozita pripravljani su postupkom polaganog sušenja iz smjese poliuretana i nanopunila u acetonu pri sobnoj temperaturi. Učinak dodatka nanopunila na sferolitnu morfologiju poliuretana te raspodijeljenost nanopunila u matrici PU analizirana je optičkom polarizacijskom mikroskopijom. Toplinska svojstva u neizotermnim i izotermnim uvjetima istraživana su diferencijalnom pretražnom kalorimetrijom (DSC). Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna., In this work, the influence of multiwalled carbon nanotubes (MWCNT) and carbon nanotubes modified with COOH groups (MWCNT-COOH) on the structure and properties of thermoplastic polyurethane (PU) were investigated. The samples of nanocomposite were prepared from a mixture of polyurethane and MWCNT in acetone by slow drying at room temperature. The effect of the addition of nanofillers on the spherulite structure of polyurethane and the distribution of the nanofillers in the PU matrix were analysed with optical polarization microscopy. Thermal properties in non-isothermal and isothermal conditions were investigated by differential scanning calorimetry (DSC). The results of contact angle measurement imply that modification of MWCNT surface with COOH groups changes its surface from hydrophobic to hydrophilic (Fig. 2 and Table 1). Optical polarization microscopy showed that the addition of both nanofillers disrupts the coarse spherulite morphology of the polyurethane matrix (Fig. 4 and Fig. 5). It was observed that, at the macro level, the modified MWCNT-COOH filler is better distributed in the PU matrix than is the MWCNT filler (Fig. 5). The DSC results showed that, in non-isothermal conditions, up to a certain amount, both nanofillers accelerate the crystallization of the soft segments of polyurethane. This effect is more pronounced in systems with MWCNT filler (Fig. 9). The results of the crystallization enthalpy during cooling showed that MWCNT filler, despite its worse distribution in the PU matrix, more significantly enhances crystallization of PU’s soft segment than does the MWCNT-COOH filler (Fig. 10). This conclusion can be ascribed to better compatibility between the nonpolar MWCNT filler and the nonpolar soft phase of the PU matrix, as well as to the previous scientific finding that functional groups at MWCNT surface decrease the nucleation effect of MWCNT. By analysing the melting peaks, it can be concluded that the PU systems with MWCNT compared to systems with MWCNT-COOH contain a higher proportion of less ordered crystalline soft phase (Fig. 11). In isothermal conditions, the MWCNT filler accelerates crystallization more significantly than does the MWCNT-COOH filler (Fig. 16). This work is licensed under a Creative Commons Attribution 4.0 International License.

U ovom radu ispitana su toplinska svojstva pripravljenog drvo-cementnog kompozita. Za izradu ispitnih uzoraka korištena je drvena vuna dobivena od crnogoričnog drveća te komercijalni portland cement, CEM II. Drvena vuna korištena za ispitivanje dobre je kvalitete i mehanička svojstva uzorka su zadovoljavajuća pri svakom ispitanom omjeru drvena vuna/cement. Povećanjem udjela cementa u uzorku bolja je prekrivenost drvene vune cementom, a toplinska svojstva se relativno manje mijenjaju. Rezultati dobiveni testom gorenja pokazuju da cementni kompozit, zbog manjeg udjela gorive tvari, oslobađa manje topline u odnosu na čistu drvenu vunu. Cilj ovog rada je stjecanje teoretskog i praktičnog znanja o mjerenju toplinskih svojstava izolacijskih materijala, načinima mjerenja, normiranim metodama, te prednostima i nedostatcima tih metoda. Toplinska svojstva su ispitana pomoću više aparatura vlastite izrade. Dobiveni rezultati ukazuju na odlična izolacijska svojstva dobivenog kompozitnog materijala gustoće 300-400 kg/m^3, no neke metode je potrebno unaprijediti u daljnjim istraživanjima. In this study thermal properties of wood-cement compound are tested. Wood wool made from pine tree is used to make samples blend with Portland cement, CEM II. Wood wool used in this paper is made from high quality tree so that her mechanical properties are satisfying in any given wood wool / cement ratio. With increase in ratio of cement in compound we can see better covering of surface of wool with cement, thermal properties aren’t changed a lot. Results gotten with burning test show that cement compound, duo to less flammable material, releases less heat compared to wood wool without cement. Priority of this work is to get some theoretical and experimental knowledge about measuring thermal properties of insolation materials, ways of measurement, standardized methods, and benefits and disadvantages of those methods. Thermal properties are tested by use of apparatus of our own making. Given results point to great insolation properties of compound material of 300-400 kg/m^3 density, but some methods are needed to be improved by farther researches.

Cilj ovog istraživanja bio je ispitati svojstva polimernih mješavina akrilonitril-butadien-stirena i polietilena niske gustoće (ABS/PE-LD) i akrilonitril-butadien-stirena i polietilena visoke gustoće (ABS/PE-HD) kao i svojstva čistih komponenata, tj. čistog akrilonitril-butadien-stirena (ABS), polietilena niske gustoće (PE-LD) i polietilena visoke gustoće (PE-HD). Uzorci su pripremljeni ekstruzijom. Ispitana su njihova mehanička i toplinska svojstva, te morfologija uzoraka. Na temelju dobivenih rezultata zaključeno je da je smjesa ABS/PE-LD 95/5 najbolja od ispitivanih po pitanju mehaničkih svojstava. The aim of this study was to examine the properties of polymeric mixtures of acrylonitrile-butadiene-styrene and low density polyethylene (ABS / PE-LD) and acrylonitrile-butadiene-styrene and high density polyethylene (ABS / PE-HD) as well as the properties of pure components, i.e. pure acrylonitrile-butadiene-styrene (ABS), low density polyethylene (PE-LD) and high density polyethylene (HDPE). Samples were prepared by extrusion. Their mechanical and thermal properties, as well as the morphology of the samples were examined. Based on the obtained results, it was concluded that the ABS / PE-LD 95/5 mixture was the best in terms of it's mechanical properties.

U novije vrijeme sve je veći interes za pronalazak materijala koji bi konkurirali na tržištu svojim dobrim svojstvima, biodegradaciji i proizvodnji iz obnovljivih izvora energije. Biopolimeri se danas sve češće koriste kako bi se smanjio negativan utjecaj na okoliš koji imaju polimeri. Jedan od poznatih biorazgradivih polimera je polilaktid. Dodatakom sintetskih ili prirodnih anorganskih materijala polimernoj matrici moguće je poboljšati svojstva polimernih materijala i sniziti cijenu koštanja materijala. U ovom radu istražen je utjecaj dodatka punila (A200, R711, R805 i R816) različitih udjela na svojstva polilaktida. Uzorci su zamiješani u Brabender gnjetilici postupkom u talini. Interakcije na međupovršini punilo/matrica ispitane su metodom mjerenja kontaktnog kuta. Mehanička svojstva i mehanizam loma ispitani su rasteznim ispitivanjem na mehaničkoj kidalici. Toplinska svojstva ispitivana su metodom diferencijalne pretražne kalorimetrije, a toplinska stabilnost termogravimetrijskom analizom. Rezultati mjerenja kontaktnog kuta s vodom ukazuju na slabu hidrofilnost površine polilaktida. Punila A200 i R816 pokazuju hidrofilnu, a R711 i R816 hidrofobnu prirodu površine punila. DSC analiza je pokazala da dodatak neobrađenog A200 i silanima obrađenog silika punila u PLA matricu nema utjecaja na staklište PLA. Punilo doprinosi porastu stupnja kristalnosti i pokazuje nukleacijski učinak na kristalizaciju PLA. U PLA kompozitima metakril silanom R711 i oktilsilanom R805 obrađeno punilo usporava kristalizaciju PLA matrice. Dodatkom različitih udjela punila toplinska stabilnost PLA matrice se povećava. Rezultati ispitivanja mehaničkih svojstava pokazali su da dodatkom punila u čistu PLA matricu nema značajnih promjena u produljenju. Sve krivulje pokazuju krti lom uz maksimalno istezanje do 4%. Najbolja mehanička svojstva pokazuju PLA/R711 kompoziti. More recently, there is an increasing interest in finding materials that would compete in the market with its good properties, biodegradation and renewable energy production. Biopolymers are increasingly used today to reduce the adverse environmental impact of polymers. One of the wide known biodegradable polymers is polylactide. By adding synthetic or natural inorganic materials to the polymer matrix properties of the polymeric materials could be improved and the price of the material could be lowered. In this study the effect of filler addition (A200, R711, R805 and R816) in different quantities in polylactide was investigated. Samples were prepared by melt mixing in a Brabender plasticoder. Interactions on the filler/matrix interphase were determinated with the contact angle measurements. Mechanical properties and mechanism of faliure were investigated with the tensile test on the universal mechanical testing machine. Thermal properties were investigated with differential scanning analysis and thermal stability with termogravimetric analysis. The results of the contact angle measurement with water show poor hydrophilicity of the polylactide surface. Fillers A200 and R816 show hydrophilic and R711 and R816 hydrophobic nature of the filler surface. From the results of the DSC measurements it is visible that addition of the filler has no influence on the PLA glass transition temperature. Addition of the filler increases the degree of crystallinity and shows nucleation effect on the PLA crystallization. In the PLA composites where silica surface is modified with metacryl silane R711 and octylsilane R805 addition of the filler decreases crystallization rate of PLA. Thermal stability is increased with the addition of silica filler in PLA matrix. The results of the mechanical properties showed that addition of silica fillers in the pure PLA matrix did not have any significant effect on the elongation. All curves show maximal elongation at break of 4%, and the best mechanical properties have PLA / R711 composites.

Cilj ovog istraživanja bio je ispitati utjecaj titanijevog dioksida kao nanopunila na svojstva polimernih mješavina PLA/PE-LD 90/10 i PLA/PE-HD 90/10, kao i na svojstva čistih komponenata, tj. čistog polilaktida (PLA), polietilena niske gustoće (PE-LD) i polietilena visoke gustoće (PE-HD). Korištena su tri nanopunila komercijalnih naziva P25 (praškasti TiO2), P25/20 (granulirani TiO2) i PC500 (praškasti TiO2). Uzorci su pripremljeni ekstruzijom te su određena njihova mehanička i toplinska svojstva, ispitana je morfologija uzoraka te su snimljeni FTIR spektri čistih komponenata. Na temelju dobivenih rezultata zaključeno je da punila povoljno utječu na sva mehanička svojstva jedino u slučaju polimerne mješavine PLA/PE-LD 90/10. Punila su poboljšala neka mehanička svojstva čiste komponente PE-LD, dok kod ostalih sustava dodatak nanopunila uzrokuje lošije mehaničko ponašanje u odnosu na nepunjene sustave. Od pripremljenih nanokompozita, najbolja svojstva je u većini slučajeva pokazao onaj koji je pripremljen dodatkom nanopunila P25. The aim of this study was to investigate the influence of titanium dioxide as a nanofiller on the properties of PLA/PE-LD 90/10 and PLA/PE-HD 90/10 polymer blends, as well as on the properties of pure polylactide (PLA), polyethylene low density (PE-LD) and polyethylene high density (PE-HD) components. Three different nanofillers were used – P25 (TiO2 powder), P25/20 (granulated TiO2) and PC500 (TiO2 powder). Samples were prepared by extrusion and their mechanical and thermal properties were investigated, as well as the morphology of the samples. Also, FTIR spectrum of PLA, PE-LD and PE-HD was recorded. Based on the results, it was concluded that fillers can improve mechanical properties of the PLA/PE-LD 90/10 blend. Fillers can also have beneficial effect on some mechanical properties of the pure PE-LD component. As for the rest of the composites, it was observed that the addition of nanofillers causes poorer mechanical behavior compared to unfilled blends and pure components. In most cases, the best properties showed nanocomposites prepared by addition of the P25 filler.

Cilj ovog rada bio je istražiti utjecaj različitih udjela polietilena (PE) na toplinska i mehanička svojstva, te morfologiju polimernih mješavina na osnovi polilaktida (PLA). Svrha miješanja PE s PLA bila je dobivanje biorazgradive polimerne mješavine sa što manjim udjelom petrokemijske sintetske komponente te sniženje cijene krajnjeg polimernog proizvoda. Kao druga komponenta u mješavinama na osnovi PLA korišteni su polietileni različitih gustoća, polietilen niske gustoće i visoke gustoće. Nadalje, s aspekta primjene polimernog proizvoda cilj je bio prevladati nedostatke PLA, kao što su visoki modul i krutost, uz zadržavanje dobrih svojstava izvorno visoke čvrstoće PLA, kako bi dobili čvrst, ali i elastičan te fleksibilan materijal. Zbog nemješljivosti komponenata nužno je dodavanje punila čija je svrha modifikacija međupovršine što omogućuje bolje povezivanje polimera i bolja mehanička svojstva. Kako bismo proučili djelovanje punila na sustav PLA/PE-LD i PLA/PE-HD, odabranim mješavinama dodano je nanopunilo CaCO3 (5 masenih %) te su ispitana svojstva pripremljenih nanokompozita. Karakterizacija čistih komponenata, mješavina i kompozita provedena je rasteznim ispitivanjem, ispitivanjem udarne žilavosti, razlikovnom pretražnom kalorimetrijom (DSC) i pretražnom elektronskom mikroskopijom (SEM). Dodatkom druge komponente, PE, dolazi do očekivanog smanjenja inicijalno visoke prekidne čvrstoće čistog PLA i do smanjenja modula i krutosti, dok se istezljivost povećava tek kod većih udjela PE u mješavinama. Najlošija svojstva kod oba sustava, s PE-LD i PE-HD, primjećuju se kod mješavina s istim udjelima oba polimera, PLA i PE. Nanopunilo je dodano mješavinama s malim udjelom polietilenske komponente. Nanopunilo se ne smješta na međupovršinu između nemješljivih polimera, ali utječe na poboljšanje svojstava sustava PLA/PE-LD. Utječe na poboljšanje čvrstoće i žilavosti, a povećava i kristalnost sustava PLA/PE-LD kojem se dodaje, dok na sustav PLA/PE-HD ne utječe značajnije. The aim of this study was to research the influence of polyethylene (PE), which is added in various amounts, on the thermal and mechanical properties, also, morphology of polymer blends based on polylactide (PLA). The purpose of blending PE with PLA was to produce a biodegradable polymer blends with a small amount of petroleum – based synthetic component and to reduce the price of final polymer product. As the second component in the PLA – based blends, polyethylenes of various densities were used, such as low density and high density polyethylene. Furthermore, from the point of application of the final polymeric product, the aim was to overcome the disadvantages of PLA, such as high modulus and stiffness, while maintaining good properties of PLA, such as high strength, to obtain firm, but elastic and flexible material. Due to the immiscibility of the components, it is necessary to add filler with the purpose to modify the interface between polymers which would provide better adhesion and mechanical properties of the material. In order to study the effect of filler on the PLA/LDPE and PLA/HDPE systems CaCO3 nanofiller (5wt. %) was added to the selected blends, and the properties of nanocomposites were tested. Pure components, blends and composites were characterized by tensile test and impact resistance examination, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). When the second component is added, it reduces the initial high strength at break of pure PLA and, also, module and stiffness, while the elasticity increases only with larger amounts of PE in blends. The worst properties for both systems, with LDPE and HDPE, are noticed for the mixtures with the same amounts of both polymers. Nanofiller was added to the mixtures with small amount of PE component. Nanofiller is not situated at the interface, but it still affects the properties of PLA/LDPE blends. Nanofiller improves strength and toughness; also it increases crystallinity of PLA/LDPE systems, but has no effect on mechanical properties of PLA/HDPE blends.

Upotreba nerazgradivih polimera kao ambalažnih materijala smatra se velikim ekološkim problemom današnjice zbog lošeg utjecaja na biljni i životinjski svijet. Folije polietilena niske gustoće (LDPE) primjenjuju se u pakiranju hrane zbog dobrih mehaničkih svojstava, dobre prerade te fleksibilnosti. Međutim nedostatak LDPE-a kao nerazgradivog ambalažnog materijala je veliki utjecaj na onečišćenje okoliša. Biljke uzgojene kao sirovine za proizvodnju prirodnih vlakana predstavljaju izvor sirovina neovisan o naftnim derivatima, pa su osobito zanimljive zbog svoje dostupnosti, obnovljivosti te prihvatljivosti s stajališta zaštite okoliša. Cilj ovog rada bio je priprava biokompozita umješavanjem prirodne lignoceluloze, rižine ljuskice (RLJ) u LDPE u svrhu dobivanja biorazgradivog polimernog materijala. Nakon priprave biokompozita s različitim udjelom rižinih ljuskica (5, 10, 15, 20, 25 i 30 mas%) ispitan je utjecaj rižinih ljuskica i njihovog udjela na toplinska svojstva LDPE/RLJ biokompozita. Toplinska stabilnost čistog LDPE-a, te LDPE/RLJ biokompozita ispitana je primjenom termogravimetrijske analize (TGA) u atmosferi dušika. Dinamičko mehaničkom analizom (DMA) određene su primarne viskoelastične funkcije, modul pohrane (E') i modul gubitka (E'') u funkciji temperature za čisti LDPE i LDPE/RLJ biokompozite, a za određivanje faznih prijelaza primijenjena je diferencijalna pretražna kalorimetrija (DSC). Na osnovi dobivenih rezultata može se zaključiti da dodatkom i povećanjem udjela RLJ stupanj kristalnosti neznatno raste što znači da RLJ djeluju kao nukleacijski agens. Temperatura početka razgradnje čistog LDPE-a pomiče se na više vrijednosti dodatkom RLJ što ukazuje na povećanje toplinske stabilnosti LDPE-a dodatkom RLJ. DMA mjerenjem dobiven je porast Tg-a dodatkom RLJ uslijed interakcija između LDPE-a i RLJ. Non-degradable polymers as a packaging materials has bad influence on the environment, cause damage to plants and animals, it's being consider as one of the greatest environmental problem today. Low density polyethylene (LDPE) sheets are used in food packaging because of their good mechanical properties, easy processing and flexibility. However the lack of LDPE as non-degradable packaging material has a major impact on environmental pollution. Plants grown as a raw material for the production of natural fibers are a source of raw material independent of petroleum products, however, are particularly interesting because of its availability, reproducibility and acceptability in terms of environmental protection. The aim of this study was to prepare biocomposites with melt mixing (compounding) of natural lignocellulose, rice husk (RH) and LDPE in order to obtain biodegradable polymer material. After preparation of LDPE/RH biocomposites with different content of rice husk (5, 10, 15, 20, 25 and 30 wt%) the influence of the rice husk and their content on thermal properties of LDPE/RH biocomposites was investigated. Thermal stability of the neat LDPE and LDPE/RH biocomposites was studied using thermogravimetric analysis (TGA) in nitrogen atmosphere. The viscoelastic properties, the storage modulus (E ') and loss modulus (E'') as a function of temperature for the neat LDPE and LDPE/RH biocomposites were obtained by dynamic mechanical analysis (DMA). The phase transitions were obtained using the differential scanning calorimetry (DSC). Results confirmed that the incorporation of the RH into the LDPE and increase oft he content oft he RH slightly increased the crystallinity which means that RH act as a nucleating agent. The initial degradation temperature of the neat LDPE is shifted to higher temperature by addition of RH which means that the thermal stability oft he LDPE increased by the addition of RH. The DMA measurements showed that the glass trasition temperature Tg of the LDPE in the blends were increased with the addition of RH. This behaviour is due to the interaction between RH and LDPE.

U ovom radu prvo su karakterizirane višestijene ugljikove nanocjevčice (MWCNT) te MWCNT modificiranih –COOH skupinama. Karakterizacija MWCNT, MWCNT-COOH provedena je Ramanovom spektroskopijom, termogravimetrijskom analizom, zatim pomoću pretražne elektronske mikroskopije, mjerenjem kontaktnog kuta, te određivanjem disperzivnosti u različitim otapalima. Zatim je istraživan učinak dodatka MWCNT te MWCNT–COOH u rasponu udjela od 0-4% mas. na svojstva poliuretana. Uzorci nanokompozita pripravljani su postupkom iz otopine poliuretana u acetonu te polaganim sušenjem otopina na sobnoj temperaturi. Učinak dodatka nanopunila na sferolitnu strukturu poliuretana te raspodjeljenost nanopunila u PU matrici anlizirana je optičkom polarizacijskom mikroskopijom. Toplinska svojstva u neizotermnim i izotermnim uvjetima istraživana su diferencijalnom pretražnom kalorimetrijom (DSC), a toplinska stabilnost termogravimetrijskom analizom (TGA). Električna provodnost uzoraka određivana je metodom četiri kontakta. Utjecaj dodatka punila na mehanička svojstva PU kompozita ispitana je testom jednoosnog istezanja. Ramanova spektroskopija pokazala je da MWCNT imaju veći udio nečistoća nego MWCNT-COOH. TGA analiza pokazala je da su MWCNT-COOH toplinski stabilnije od MWCNT. Rezultati SEM analize pokazali su da funkcionalizacija ne utječe na stupanj agregacije. Rezultati kontaktni kuteva ukazuju da se funkcionalizacijom s -COOH skupinom uvelike mijenja polarnost nanocijevčica. Rezultati određivanja disperzivnosti pokazali su da su obe vrste nanocjevčica jako dobro dispergirane u acetonu. Optička polarizacijska mikroskopija pokazala je da dodatak oba punila razrušava krupnu sferolitnu morfologiju poliuretana. Uočeno je da su na makrorazini modificirane MWCNT-COOH bolje dispergirane u masi uzorka nego čiste MWCNT. DSC rezultati pokazali su da u neizotermnim uvjetima do određenog udjela dodatak obje vrste MWCNT ubrzavaju kristalizaciju mekog segmenta poliuretana. U uvjetima izotermne kristalizacije MWCNT također znatnije ubrzavaju kristalizaciju nego MWCNT-COOH. Rezultati termogravimetrijske analize upućuju da se dodatkom obje vrste MWCNT znatno poboljšava toplinska stabilnost u čitavom rasponu udjela nanopunila. Rezultati vodljivosti pokazali su da se i dodatakom malih udjela MWCNT vodljivost znatno povećava. Rezultati ispitivanja mehanički svojstava nanokompozita ukazuju da dodatak obje vrste MWCNT punila snižava prekidnu čvrstoću i prekidno istezanje kompozita. In this study carbon nanotubes (MWCNTs) and MWCNTs modified with COOH groups were characterized. Characterization of MWCNTs, MWCNTs-COOH was performed by Raman spectroscopy, thermal analysis, then using scanning electron microscopy, by measuring the contact angle, and determining dispersibility in various solvents. After that the effect of the addition of MWCNTs and MWCNTs-COOH in range of 0-4% wt. on the properties of polyurethane were investigated. Samples of nanocomposite were prepared from solution of polyurethane in acetone and slowly drying the solution at room temperature. The effect of the addition of nanofiller on spherulite structure of polyurethane and distribution nanofiller in PU matrix were analyzed by optical polarization microscopy. Thermal properties in the non-isothermal and isothermal conditions were investigated by differential scanning calorimetry (DSC) and thermal stability by thermogravimetric analysis (TGA). The electrical conductivity of the samples was determined using four probe method. Effect of the addition of fillers on the mechanical properties of PU nanocomposites was examined by uniaxial deformation test. Raman spectroscopy showed that MWCNTs have a higher proportion of impurities than MWCNTs-COOH. TGA analysis showed that MWCNTs-COOH are more thermally stable than MWCNTs. The results of SEM analysis showed that the functionalization does not affect the degree of aggregation. The results of the contact angles indicate that the functionalization by COOH groups significantly changes the polarity of the nanotubes. The results of determining dispersibility showed that both types of nanotubes are very well dispersed in the acetone. Optical polarization microscopy showed that the addition of both nanofillers disrupts the spherulite morphology of polyurethane. It was noted that at the macro level modified MWCNTs-COOH are better distributed in the the sample than pure MWCNTs. DSC results showed that in the non-isothermal conditions up to the addition of a certain amount of both types of MWCNTs accelerate the crystallization of the soft segments of polyurethane. In terms of isothermal crystallization MWCNTs also significantly accelerate crystallization than MWCNTs-COOH. The results of thermogravimetric analysis indicate that the addition of both types of MWCNTs significantly improves the thermal stability. Conductivity results showed that the the addition of small amount of MWCNTs significantly increases the conductivity. The results of the mechanical properties of the nanocomposite show that addition of both types of fillers MWCNTs reduced tensile strength and elongation of the composite.

Cilj ovog rada bio je pripremiti i karakterizirati LDPE/ PCL mješavine s naglaskom na primjenu kao ambalažnog materijala, te odrediti samu mješljivost mješavina različitih masenih omjera. Mješavine polietilena niske gustoće (LDPE) i polikaprolaktona (PCL) u različitim omjerima (100/0, 90/10, 70/30, 50/50, 30/70, 10/90 i 0/100 mas%) pripravljene su umješavanjem u Brabender gnjetilici. Uzorci mješavina dobiveni su prešanjem na hidrauličkoj preši. Upotreba nerazgradivih polimera kao ambalažnog materijala ima loš utjecaj na okoliš te štete biljnom i životinjskom svijetu pa se uz kisele kiše, globalno zatopljenje, nestanak biljnih i životinjskih vrsta, plodnog tla i ozonskog omotača smatraju jednim od najvećih ekoloških problema današnjice. Folije polietilena niske gustoće (LDPE) primjenjuju se u pakiranju hrane zbog dobrih mehaničkih svojstava, dobre prerade te fleksibilnosti. Međutim, nedostatak LDPE-a kao nerazgradivog ambalažnog materijala je veliki utjecaj na onečišćenje okoliša. Doprinos istraživanja bio bi razvoj novih biorazgradivih materijala koji bi našli primjenu kao ambalažni materijal za pakiranje plodova u voćarstvu. Za karakterizaciju čistih LDPE, PCL i LDPE/PCL mješavina koristila se tehnika diferencijalne pretražne kalorimetrije (DSC), dinamičko-mehaničke analize (DMA) i termogravimetrijska analiza (TGA). Pomak staklišta jednog prema drugom ukazuje na djelomičnu mješljivost LDPE i PCL. Toplinska stabilnost LDPE-a se povećava dodatkom i povećanjem udjela PCL što je vidljivo iz pomaka temperature razgradnje LDPE-a na više temperature. The aim of this work was to preparation and characterization of LDPE/ PCL blends and their application as a packaging materials as well as to determin the miscibility of LDPE/PP blends. Blends of low-density polyethylene (LDPE)/poly (ε-caprolactone) (PCL), (LDPE/PCL) were prepared with melt mixing (compounding) in Brabender mixer under different LDPE/ PCL content (100/0, 90/10, 70/30, 50/50, 30/70, 10/90 and 0/100 wt%). The specimens of neat polymers and LDPE/PCL blends were molded in hydraulic press. Non-degradable polymers as a packaging materials has bad influence on the environment, cause damage to plants, animals and along with acid rains, global warming, disappearance of plant and animal species, fertility of the soil, ozone layer it's being consider as one of the greatest environmental problem today. Low-density polyethylene (LDPE) sheets are used in food packaging because of it's good mechanical properties, easy processing and flexibility. However, the lack of LDPE as non-degradable packaging material is huge environmental pollution. Contribution of this research would be development of new, biodegradable materials which can be use in packaging fruit in fruitgrowing. The thermal properties of neat LDPE, PCL polymers and their blends and LDPE/ PCL blends were investigated by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The shift of glass transition temperature (Tg) indicated that LDPE and PCL are partially miscible. The thermal stability of the composites was enhenced with the addition of PCL and increase of the PCL content.

Ispitivanje toplinskih svojstava materijala često se provodi metodama koje su dugotrajne i većinom nepristupačne. Cilj ovog rada je bio osmisliti aparaturu pomoću koje će se na jednostavan način utvrditi neko toplinsko svojstvo materijala. Osnovna aparatura korištena u eksperimentu nadograđena je verzija aparature koja je korištena u prethodnim istraživanjima na Zavodu za anorgansku tehnologiju i nemetale, odnosno korišten je još jedan Peltierov element. Rezultati mjerenja su kvalitativnog karaktera, odnosno može se usporediti toplinska vodljivost različitih materijala ili istog materijala različitih debljina. Zbog nedostatka iskustva i vremena nije napravljen matematički model pomoću kojeg bi mogli dobiti i kvantitativni rezultat. Testing thermal properties of materials are often performed by methods that are longlasting and most inaccessible. The aim of this study was to design an apparatus which will help with easy determination of thermal properties of the material. The basic apparatus used in experiment is a upgraded version of apparatus that was used in previous studies in the Department of Inorganic technology and non-metals in which is added one more Peltier element. The measurement results are qualitative character and can be used to compare the thermal conductivity of different materials or the same material of varying thickness. Due to lack of experience and time, we haven't made a mathematical model with which we could get also a quantitative result.

Novi trendovi u istraživanjima su pronalazak materijala koji bi konkurirali na tržištu svojim dobrim svojstvima, biodegradabilnosti i proizvodnji iz obnovljivih izvora energije. Polilaktid je jedan od takvih materijala, koji s dodatkom ugljikovih nanocjevčica može konkurirati na tržištu. U ovom radu provedena su istraživanja utjecaja dodatka različitih masenih udjela funkcionaliziranih ugljikovih nanocjevčica (MWCNT-COOH; MWCNT-COOC12H25) u polilaktid. Uzorci su zamiješani na Brabender gnjetilici postupkom u talini. Potom je ispitivana morfologija, mehanička svojstva i mehanizam loma pomoću mehaničke kidalice i pretražnog elektronskog mikroskopa. Toplinska svojstva ispitivana su metodom diferencijalne pretražne kalorimetrije, te toplinska stabilnost termogravimetrijskom analizom. Električna svojstva određivana su mjerenjem otpora metodom četiri probe. Rezultati su pokazali da se mehanička svojstva PLA sustava s MWCNT-COOH i MWCNT-COOC12H25 nanopunilima poboljšavaju najznačajnije do 2 % mas. PLA nanokompoziti (do 2 % mas.) s ugljikovim nanocjevčicama funkcionaliziranim dugim alkilnim lancima (MWCNT-COOC12H25) imaju nešto bolja svojstva od sustava s MWCNT-COOH zbog bolje raspodijeljenosti MWCNT-COOC12H25 punila, što je potvrđeno analizom površine kidanja. Rezultati DSC analize pokazali su da dodatak oba punila ubrzava neizotermnu kristalizaciju PLA matrice i to najznačajnije do 2 % mas. Dodatak MWCNT-COOC12H25 punila zbog dugog alkilnog lanca koji ulazi u matricu znatnije ometa slaganje polimernih lanaca u kristalne forme. Neovisno o vrsti funkcionalnih skupina graftiranih na površini MWCNT tijekom procesa hladne kristalizacije u PLA nanokompozitima stvara se veći udio slabije uređenih struktura nego u čistoj PLA matrici. Toplinska stabilnost najznatnije se poboljšava dodatkom do 2 % mas. punila. Ovakvi rezultati se pripisuju učinku barijere koju stvaraju ugljikove nanocjevčice i dobroj toplinskoj vodljivosti MWCNT. Nije vidljiva znatna razlika u poboljšanju toplinske stabilnosti ovisno o funkcionalnoj skupini graftiranoj na ugljikovu nanocjevčicu. Rezultati ispitivanja električne vodljivosti pokazuju značajno poboljšanje vodljivosti već dodatkom malih količina funkcionaliziranih MWCNT do 0,5 % mas. zbog nastajanja trodimenzionalne vodljive mreže u matrici te istraživani nanokompoziti imaju potencijalnu primjenu za elektrostatsko bojanje i odvođenje elektrostatskog naboja. New trends in research are finding materials who would compete in open market with it's properties, biodegradability and production from renewable sources of energy. Polylactide is one of those materials, and with addition of carbon nanotubes it can compete in the open market. In this study the addition of different quantities of modified carbon nanotubes (MWCNT-COOH; MWCNT-COOC12H25) in PLA was investigated. Samples were prepared by melt mixing in a Brabender plasticoder. Within this study morphology, mechanical properties and mechanism of failure with scanning electron microscopy (SEM) and universal mechanical testing machine were investigated. Thermal properties were investigated by differential scanning analysis and thermal stability was determined by thermogravimetric analysis. Electrical properties were investigated by measuring resistance using four probe method. Results showed the most significant increase of mechanical properties for PLA systems with MWCNT-COOH and MWCNT-COOC12H25 nanofillers up to 2 % wt. PLA nanocomposites (up to 2 % wt) with carbon nanotubes functionalized with long alkyl chains (PLA/MWCNT-COOC12H25) have slightly better properties than systems with MWCNT-COOH due to better distribution of MWCNT-COOC12H25 in PLA matrix, which is confirmed also by fracture surface analysis. DSC results indicate that addition of both fillers accelerates nonisothermal crystallization of PLA matrix and this effect is more pronounced up to 2 % wt. Addition of MWCNT-COOC12H25 nanofiller, due to long alkyl chains that entrance in a matrix, more significantly hinders ordering of polymer chains in the crystalline form. Regardless of the type of grafted functional groups on the surface of MWCNTs, during the cold crystallization a higher proportion of lower-ordered structures than in a pure PLA matrix were created. The most prominent improvement of thermal stability is obtained by the addition of 2% wt of fillers. These results can be attributed to formation of barrier that carbon nanotubes formed and to the very high thermal conductivity of MWCNTs. Depending on the type of functional groups on the carbon nanotubes difference in the improvement of the thermal stability were not observed. The results of electrical conductivity show significant improvement of conductivity with addition of small amounts of functionalized MWCNTs up to 0.5% wt due to the formation of three-dimensional conductive network in the PLA matrix. The investigated nanocomposites have potential use for electrostatic painting and dissipation of electrostatic charge.

PVC, poli(vinil-klorid) je jedan od toplinski najnestabilnijih polimera. Među velikim brojem dodataka koji su potrebni PVC-u za njegovu uspješnu preradu, značajno mjesto zauzimaju anorganski materijali tj. punila. Od posebnog je interesa istraživanje dodatka nano i mikropunila te njihov utjecaj na svojstva kompozita. U ovom radu ispitivana je morfologija, mehanička i toplinska svojstva poli(vinil-klorida) uz dodatak različitih masenih udjela punila. Korišteno je prirodno punilo perlit mikrodimenzija i sintetsko nanopunilo pirogena silika. Temperatura staklastog prijelaza određivana je diferencijalnom pretražnom kalorimetrijom (DSC), a toplinska stabilnost metodom termogravimetrijske analize (TGA). Morfologija čestica punila, raspodjela punila u PVC matrici te mehanizam popuštanja određeni su pretražnim elektronskim mikroskopom(SEM). Mehanička svojstva polimerne matrice PVC te kompozitnih sustava određivana su testom jednoosnog istezanja na mehaničkoj kidalici. Kompozitima je određena i tvrdoća, mjerenjem shoremetrom A. Rezultati su pokazali da dodatak punila ne utječu na temperaturu staklastog prijelaza. Ispitivanjem toplinske stabilnosti pokazalo se kako dodatak perlita poboljšava toplinskasvojstva PVC-a, dok dodatkom aerosila dolazi do promjene toplinskih svojstava tek pri višim koncentracijama. Analiza mehanizma popuštanja i mehaničkih svojstava upućuje da dodatak perlita pogoršava mehanička svojstava; smanjuje vrijednost prekidne čvrstoće, prekidnog istezanja i rada kidanja u odnosu na čistu PVC matricu. Aerosil nije utjecao na promjenu mehaničkih svojstava PVC matrice. Dodatak oba punila povećao je tvrdoću PVC matrice. PVC, poly(vinyl chloride) is one of the most thermally unstable polymers. Among the large number of supplements required for successful treatment of PVC, significant place have inorganic materials i.e. fillers. Special interests of researchers are nano and microfillers and their influence on the composite properties. In this study, mechanical and thermal properties of poly(vinyl chloride) with different amount of the fillers have been studied. The fillers which were used are natural filler perlite and synthetic filler pyrogenic silica. Glass transition temperature was determined with differential scanning calorimetry (DSC) and thermal stability with thermogravimetric analysis (TGA). Mechanical properties of the PVC polymer matrix and PVC composites were determined on mechanical testing machine by tensile test. To investigate the morphology of the filler particles, distribution of the filler in polymer matrix and the failure mechanism,scanning electron microscope (SEM) was used. Hardness of the PVC and PVC composites were determined using shoremeter A. Results showed that the addition of both fillers did not influence on the PVC glass transition temperature. Analysis of thermal stability has shown that the addition of perlite improves thermal stability of PVC, while aerosil affects PVC's thermal stability only at higher concentration. Analysing the mechanism of failure and mechanical properties, it was concluded that the addition of perlite have negative influence on mechanical properties. In general, the addition of perlite reduces all mechanical characteristic values such as tensile strength, elongation at break and work of break. Aerosil did not affect mechanical properties of the PVC matrix. Addition of both fillers increased the hardness of PVC matrix.

Za razliku od prirodnih polimera, većina sintetskih polimera ne može se razgraditi mikroorganizmima, te ovi polimeri predstavljaju veliki problem za okoliš stoga se istražuje drugi način njihovog zbrinjavanja. Danas postaje vrlo važno istraživanje biorazgradivih svojstava sintetskih polimera. Dolazi do razvoja novih tehnika u cilju dobivanja ekološki prihvatljivih polimera. Za rješavanje problema zbrinjavanja polimernih materijala i dobivanje ekološki prihvatljivih polimernih materijala primjenjuje se modifikacija nebiorazgradivih sintetskih polimera s biorazgradivim polimerima. Glavni problem u modifikaciji nerazgradivih sintetskih polimera s biorazgradivim polimerima predstavlja kompatibilnost polimernih mješavina s različitim svojstvima. Polipropilen (PP) je termoplastični polimer koji se u okolišu teško razgrađuje mikroorganizmima. Unatoč brojnim komercijalnim primjenama, nedostatak polipropilena su slabe interakcije i kombatibilnost s drugim polimernim materijalima. Cilj ovog rada je poboljšanje svojstva PP, kao i njegove biorazgradivosti miješanjem s biorazgradivim poliester polikaprolaktonom (PCL). PCL je netoksični, biološki razgradiv polimerni materijal koji se miješa s različitim sintetskim polimerima u različitim omjerima. Glavni problem je u pripremi PP/PCL polimernih mješavina je njihova kompatibilnost . U ovom radu prikazani su rezultati toplinskih svojstva i kompatibilnosti PP/ PCL mješavina ojačanih česticama nano titan dioksida (nTiO2) te utjecaj nTiO2 na toplinska svojstva kao i na kompatibilnost. Titanijev dioksid često se koristi kao anorgansko punilo zbog svoje dobre mehaničke čvrstoće. Čisti uzorci, mješavine PP/PCL s dodatkom i bez dodatka nTiO2 pripremljeni su u dvopužnom ekstruderu Rondol 21 mm LAB TWIN , granule polimernih mješavina prešane su na hidrauličkoj preši Dake Model 44-226. Za istraživanje toplinskih svojstava čistih polimera, te polimernih mješavine s dodatkom i bez dodatka nTiO2 korištene su tehnike diferencijalne pretraže kalorimetrije (DSC) i dinamičko mehanike analize (DMA). Unlike natural polymers, most synthetic polymers can not be decomposed by microorganisms, hence the landfill approach becomes inefficient, and other plastics waste management should be found. A study of the biodegradation properties of synthetic polymers has become very important. New techniques have been developed to obtain environmentally friendly polymers. A modification of non-biodegradable synthetic polymers with a biodegradable polymer producing environmentally friendly polymers is an established technique to solve this problem. The main problem in modification of non-biodegradable synthetic polymers with biodegradable polymers is compatibility between polymers mixtures with different properties. Polypropylene (PP) is a thermoplastic polymer and difficult to be decomposed by microorganisms in environment. Despite its many commercial application, polypropylene suffers a major deficiency that is poor interaction and compatibility with other materials. The aim of this work is to improve the properties of PP as well as its biodegradability by blending with biodegradable polyester polycaprolactone (PCL). PCL is nontoxic, biodegradable polymer material and can be blended with various synthetic polymers over a wide composition range. The main problem in preparation of PP/PCL polymer blends is compatibility between polymers. In this work is presented results of thermal properties and compatibility of PP and PCL polymer blends reinforced with nano sized titan dioxide (TiO2) particles as well as effect of nTiO2 reinforcement on the thermal properties and compatibility. Titan dioxide, one of the inorganic materials with high mechanical strengths, is used as reinforcement material for polymers. The neat polymers, PP/PCL and PP/PCL (nTiO2) polymer blends were prepared by melt compounding with a twin screw extruder Rondol 21 mm LAB TWIN , the granules of the blends were compression molding in hydraulic press. The thermal properties of the neat polymers, PP/PCL and PP/PCL/nTiO2 blends are measured using the differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) techniques.

Raširena primjena toplinske analize kao znanstvene laboratorijske tehnike dovela je do razvoja radnih naziva. Nakana je ovog dokumenta pružiti svima koji se bave toplinskom analizom međusobno usklađene definicije koje će omogućiti jasnu i preciznu komunikaciju i sporazumijevanje. Dokument sadrži definicije 13 tehnika, 54 pojma u glosaru te simbole i jedinice., The widespread use of thermal analysis (TA) by scientists as a laboratory technique carries with it a working vocabulary. This document is intended to provide those working in the field with a consistent set of definitions to permit clear and precise communication as well as understanding. Included in the document are the definitions of 13 techniques, 54 terms within the glossary, as well as symbols and units.

Dokument definira nazive vezane uz ustaljenu toplinsku i termomehaničku karakterizaciju polimernih materijala., The document gives definitions of terms met in the conventional thermal and thermomechanical characterisation of polymeric materials.