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U ovom radu istraţivana je mogućnost modifikacije poli(etilen-oksida) (PEO) s poli(etilen-glikol) poliedarskim oligomernim silseskvioksanom (PEG-POSS) u svrhu smanjenja kristalne faze polimera, odnosno poboljšanja njegove ionske provodnosti. U tu svrhu pripravljeni su uzorci u kojima je PEO modificiran s 5 %, 10 % i 15 % PEG-POSS-a te uzorci u koje je još dodana i sol litijev bis(oksalat) borat (LiBOB) u omjeru kisika iz PEO-a i litija iz soli 8:1. Uzorci su pripravljeni dinamiĉkom metodom iz taljevine u dvopuţnom ekstruderu, koja osigurava dobru dispergiranost punila i soli u polimernoj matrici, te su dobiveni rezultati usporeĊeni s rezultatima istraţivanja ovih uzoraka pripravljenih miješanjem iz taljevine statiĉkom metodom. NaĊeno je da dodatak PEG-POSS-a ne utjeĉe znaĉajno na temperature faznih prijelaza PEO-a, kao ni na udio kristalne faze. PEG-POSS ne utjeĉe na toplinsku stabilnost PEO-a. Stoga se ovakvi rezultati ne pripisuju lošoj dispergiranosti punila, što se pretpostavljalo kod statiĉke priprave uzoraka, već se zakljuĉuje da PEG-POSS ne utjeĉe ni na toplinska svojstava PEO-a niti na formiranje kristalne faze PEO-a. TakoĊer je naĊeno da sol LiBOB potpuno narušava kristalnu fazu PEO-a te da povećava temperaturu poĉetka razgradnje PEO-a za 13 °C, dok vrijednost staklišta povećava za desetak stupnjeva. Ipak, rezultati elektrokemijske impedancijske spektroskopije pokazuju da dodatak PEG-POSS-a ima utjecaja na ionsku provodnost. Uzorak kojem je dodano 15 % PEG-POSS-a i Li sol pokazuje najveću vrijednosti ionske provodnosti. In this work, the possibility of modifying poly(ethylene oxide) (PEO) with poly(ethylene glycol) polyhedral oligomeric silsesquioxane (PEG-POSS) was investigated for the purpose of reducing the crystalline phase of the polymer or improving his ionic conductivity. For this purpose, samples were prepared in which PEO was modified with 5, 10 and 15 % PEO-POSS and samples in which lithium bis(oxalate) borate salt was also added in the ratio of oxygen from PEO and lithium from salt 8:1. The samples were prepared by the dynamic method from the melt in a twin screw extruder, which ensures good dispersion of the filler and salt in polymer matrix, and the obtained results were compared with the results of the research of these samples prepared by mixing from the melt using the static method. It was found that the addition of PEG-POSS does not significantly affect the phase transition temperatures of PEO, as well as the proportion of the crystalline phase. PEG-POSS does not affect the thermal stability of PEO. Therefore, these results are not attributed to the poor dispersibility of the filler, which was assumed in the static preparation of the samples, but it is concluded that PEG-POSS does not affect either the thermal properties of PEO or the formation of the crystalline phase of PEO. It was also found that the LiBOB salt completely destroys the crystalline phase of PEO and that it increases the temperature of the beginning of PEO decomposition by 13 °C, while the value of the glass transition increases by ten degrees. Nevertheless, the results of electrochemical impedance spectroscopy show that the addition of PEG-POSS has an effect on ionic conductivity. The sample to which 15% of PEG-POSS and Li salt were added shows the highest values of ionic conductivity.

U ovom radu provedena je karakterizacija i identifikacija mikroplastike pronađene u sedimentu plaže Zaglav na otoku Visu. Uzorkovanje i separaciju uzoraka proveo je Institut za oceanografiju i ribarstvo u Splitu. Karakterizacija mikroplastike izvršena je na 865 uzoraka s plaže Zaglav na otoku Visu. Uzorci su vizualno analizirani i svrstani prema obliku definiranim prema DeFishGear protokolu: filamenti, filmovi, fragmenti, granule, peleti i pjene. Svakom pojedinačnom uzorku je vizualno određena prozirnost i boja, a masa vaganjem na analitičkoj vagi. Površina i maksimalna dimenzija svakog ispitka određeni su upotrebom Digimizer programskog paketa. Identifikacija vrste polimernog materijala o kojem je riječ provedeno je za 865 uzoraka uz pomoć FTIR spektroskopije i diferencijalne pretražne kalorimetrije, dok su sitniji uzorci ostavljeni za analizu naprednijim tehnikama. Ustanovljeno je da su fragmenti najzastupljenija kategorija, a uzorci su većinom neprozirni i bijele boje, čestice promjera manje od 5 mm što ih svrstava u kategoriju mikroplastike. Najzastupljenija vrsta polimernog materijala je polipropilen, nakon kojeg slijede polietilen visoke gustoće i polietilen niske gustoće. Rezultati koji su dobiveni ovim istraživanjem ukazuju da najveći broj uzoraka sedimenta plaže Zaglav na otoku Visu potječe od nepropisno odložene jednokratne ambalaže. This thesis shows characterization and identification of microplastic waste found in the Zaglav beach sediment on Vis island. Sampling and separation of samples was performed by the Institute of Oceanography and Fisheries in Split. Characterization of microplastic was performed on 865 specimens from the Zaglav beach on Vis island. Specimens were visually analysed and sorted into categories according to shape defined by DeFishGear protocol: filaments, films, fragments, granules, pellets and foams. Transparency and color of the individual specimens are visually determined and a mass was determined using an analytical balance. Area and maximum dimension were determined using software package Digimizer for image processing. Identification of the type of polymer material was performed by FTIR spectroscoopy and diferential scanning calorimetry, while other smaller specimens were left for the further analysis using more precisely methods. The most common category is fragments, spesimens are mostly white in color and opaque, particles less than 5mm in diameter which sorts them in category of microplastics. The most common type of polymer material is polypropylene, followed by polyethylene high density and polyethylene low density. Results obtained by this research show that most specimens from Zaglav beach originate from improperly discarded disposable packaging.

Termoodskočni materijali proučavaju se više od 30 godina ne samo zbog znanstvenog i industrijskog potencijala, nego i svoje atraktivne i tajanstvene prirode. Kako samo ime govori, termoodskočni materijali su kristali kojih pri grijanju ili hlađenju dolazi do faznog prijelaza koji je toliko ekstremno brz i energičan da kristali odskakuju sa podloge na udaljenosti koje su višestruko veće od njihovih dimenzija. Uz sami termoodskočni (TO) efekt, postoje i popratne pojave koje su karakteristične tim materijalima kao što je negativna termička ekspanzija. U ovom se radu pokazuje novootkriveni termoodskočni efekt kod 8 različitih spojeva a istražuje se u materijalu triphenyltetrazolij kloridu (TTC) i pokazuju se okolnosti pri kojima se pojavljuje. U tu svrhu korištene su sljedeće eksperimentalne i računalne metode: rendgenska difrakcija u polikristalu, mikroskopija sa grijaćom pločom, diferencijalna pretražna kalorimetrija, računalni software X’Pert Highscore Plus (u svrhu analize difrakcijskih mjerenja) i drugi alati za statističku obradu podataka i grafičku obradu slika. Napravljeno je cjelokupno istraživanje u temperaturnom intervalu od -186° C do temperature tališta od 250° C kako bi se stvorila potpuna slika o prisutnom TO efektu. Ispitani su brojni uzorci od kojih su neki rekristalizirani u 3 različita otapala: vodi, acetonu i etanolu i uočeno je bogato “ponašanje” navedenog spoja: čak pet različitih temperaturnih intervala “skakanja”, pojava negativne termičke ekspanzije, polimorfizam i šest različitih faza iznad i ispod sobne temperature. Također je opažena histereza temperature TO efekta prilikom grijanja i hlađenja. Thermosalient materials are being studied for more than 30 years, not just for its scientific and industrial potential, but because of its attractive and mysterious nature. As the name says, thermosalient or “jumping” materials are crystals which when heated or cooled down undergo a phase transition which is so sudden and energetic that they jump off up to distances several times larger than their dimensions. Thermosalient effect is usually accompanied with other specific phenomena such as negative thermal expansion. In this work thermosalient effect is demonstrated for the first time in 8 different materials with special attention given to Triphenyltetrazolium Chloride (TTC) and circumstances under which it occurs are shown. For this purpose different experimental and computational methods such as powder x-ray diffraction (PXRD), hot stage microscopy, differential scanning calorimetry, X‘Pert Highscore Plus (for analysis of diffraction measurements) computer software and other tools for statistical data processing and graphical image processing were used. The entire study was performed at a temperature range of -186° C to the melting point of 250° C to fully characterize TO effect in this system. Numerous samples were tested, some of which were recrystallized from 3 different solvents: water, acetone and ethanol, and the rich “behaviour” of the titled compound was observed. As many as five different temperature intervals of jumping, the appearance of negative thermal expansion polymorphism and six different phases above and below room temperature. Hysteresis of the temperature of TO effect was also observed.

Poly(lactic acid) (PLA), compared to other biodegradable polymers, has one of the highest consumption volumes in the world. Due to its specific properties, especially those that make it ecologically acceptable, it has a wide application from food packaging to medical implants. In this work, commercially available 3D printing filament of PLA was used. The objective was to investigate the effects of γ-radiation on structural changes, mechanical and thermal behaviour of the material. The samples were irradiated with total doses of 25 kGy, 50 kGy, 100 kGy and 200 kGy. The experimental techniques used to investigate the structural changes in PLA filaments were electron spin resonance (ESR) and gel permeation chromatography (GPC). Differential scanning calorimetry (DSC) and universal testing machine were applied in monitoring changes in thermal and mechanical behaviour, respectively. The formation and stability of free radicals were studied by ESR, which confirmed that the radical concentration depends on the applied absorbed dose, while the spectral lineshape appears to be dose independent. The loss of the ESR signal, directly related to the decrease of radical concentration, was monitored as a function of time for all applied absorbed doses. The breaking force and the Young's modulus were determined and compared. Results have shown that both the concentration and decay rate constant of radicals depend on the absorbed dose. Compressive strength test, a new approach in considering the mechanical changes in irradiated PLA indicated a loss of material elasticity and an increase of brittleness by increasing absorbed dose.

Svrha ovog rada bila je pripremiti uzorke kompozita PEO/ES razliĉitih sastava na laboratorijskom ekstruderu pri ĉemu tijekom ekstrudiranja nije došlo do toplinske razgradnje. Pomoću infracrvene spektroskopije Fourierovom transformacijom istraživan je utjecaj mljevenih ljuskica jaja na strukturu poli(etilen-oksida) i postojanje možebitnih interakcija u kompozitima. Zakljuĉeno je kako dodatak mljevenih ljuskica jaja ne utjeĉe na strukturu PEO-a. Diferencijalna pretražna kalorimetrija primijenjena je kako bi se utvrdio utjecaj dodatka mljevenih ljuskica jaja na toplinska svojstva PEO-a. Dodatak mljevenih ljuskica jaja neznatno utjeĉe na vrijednosti staklišta, dok talište i kristalište PEO-a praktiĉki ostaju nepromijenjeni. Utjecaj dodatka mljevenih ljuskica jaja na toplinsku stabilnost PEO-a istraživana je primjenom termogravimetrijske analize. Može se zakljuĉiti da dodatak mljevenih ljuskica jaja neznatno utjeĉe na povećanje toplinske stabilnosti PEO-a u istraživanim kompozitima. The purpose of this study was to prepare samples of PEO/ES composites of different compositions on the laboratory extruder without thermal degradation. The effect of ground egg shells on the structure of poly(ethylene oxide) and the existence of possible interactions in composites were investigated by Fourier infrared spectroscopy. It was concluded that the addition of ground egg shells does not affect the structure of the PEO. Differential scanning calorimetry was applied to determine the effect of the addition of ground egg shells on the thermal properties of PEO. The addition of ground egg shells slightly affects the values of the glass, while the melting point and crystalization of PEO practically remained unchanged. The influence of the addition of ground egg shells on the termal stability of PEO was investigated using thermogravimetric analysis. It can be concluded that the addition of ground egg shells slightly affects the increase of the thermal stability of PEO in the investigated composites.

U ovom radu sintetiziran je poli(vinil-alkohol) (PVAL) alkoholizom poli(vinil-acetata) (PVAC) te je napravljena karakterizacija sintetiziranog i izvornog (kupljenog) PVAL-a pomoću infracrvene spektroskopije s Fourierovom tranformacijom (FT-IR) koja je primijenjena za potvrdu strukture polimera, odnosno uspješnosti sinteze PVAL-a alkoholizom poli(vinil-acetata), zatim diferencijalnom pretražnom kalorimetrijom (DSC) koja daje uvid u toplinska svojstva PVAL-a i termogravimetrijskom analizom (TG) s kojom se dobije uvid u toplinsku razgradnju PVAL-a. Usporedbom FT-IR spektrograma izvornog i sintetiziranog PVAL-a dobiven je koeficijent korelacije 89,5%. Te vrijednosti nisu dovoljno velike da bi potvrdile da se zaista radi o PVAL-u, međutim, prikazuju karakteristične vibracijske vrpce za čisti PVAL s blagim odstupanjem čime se dokazuje da je PVAL uspješno sintetiziran. DSC normaliziranim krivuljama potvrđeni su zaključci dobiveni FT-IR-om, ali temeljem vrijednosti staklišta, kristališta i tališta. Preklapanjem DTG krivulja dolazi se do istog zaključka, bliski rezultati u razgradnim stupnjevima potvrđuju da je sinteza PVAL-a alkoholizom PVAC-a uspješno provedena. In this paper poly(vinyl alcohol) (PVAL) was synthesized by the alcoholysis of poly(vynil acetate) (PVAC) and characterization of synthesized and original (purchased) PVAL was preformed using infrared spectroscopy with Fourier transform (FT-IR) which was applied to confirm the structure of the polymer or the success of the synthesis PVAL by the alcoholysis of PVAC, followed by differential scanning calorimetry (DSC) which gave an insight into the thermal properties of PVAL and thermogravimetric analysis which gives an insight into thermal decomposition of PVAL. By comparing FT-IR spectrograms of original and synthesized PVAL, correlation coefficient 89,5% was obtained. These values are not large enough to confirm that it is indeed PVAL however they show the characteristic vibration bands for pure PVAL with a slight deviation thus proving that PVAL has been succesffully synthesized. DSC normalized curves confirm the conclusions obtained by FT-IR but based on the glass, crystal and melting point. By overlapping the DTG curves the same conclusion was reached, close results in the degradation steps confirm that the synthesis of PVAL by the alcoholysis of PVAC was successfully implemented.

U ovom radu sintetiziran je poli(vinil-acetat) (PVAC) emulzijskom polimerizacijom vinil-acetata napravljena je karakterizacija sintetiziranog i izvornog (kupljenog) PVAC-a pomoću infracrvene spektroskopije s Fourierovom tranformacijom (FT-IR) koja je primijenjena za potvrdu strukture polimera, odnosno uspješnosti sinteze PVAC-a emulzijskom polimerizacijom vinil-acetata, zatim diferencijalnom pretraţnom kalorimetrijom (DSC) koja je dala uvid u toplinska svojstva PVAC-a i termogravimetrijskom analizom (TG) koja je dala uvid u toplinsku razgradnju PVAC-a. Usporedbom FT-IR spektrograma izvornog i sintetiziranog PVAC-a dobiven je koeficijent korelacije 87,7% te vrijednost nije dovoljno velika da bi potvrdila da se zaista radi o PVAC-u, meĊutim karakteristiĉne vibracijske vrpce za ĉisti PVAC s blagim odstupanjem ĉime se dokazuje da je PVAC uspješno sintetiziran. DSC normaliziranim krivuljama potvrĊuju se zakljuĉci dobiveni FT-IR-om, ali temeljem vrijednosti staklišta. Preklapanjem DTG krivulja dolazi se do istog zakljuĉka, bliski rezultati u razgradnim stupnjevima potvrĊuju da je sinteza PVAC-a emulzijskom polimerizacijom vinil-acetata uspješno provedena. In this thesis, poly(vinyl acetate) (PVAC) was synthesized by emulsion polymerization of vinyl- acetate and the characterization of synthesized and original (purchased) PVAC was performed using infrared spectroscopy with Fourier transform (FT-IR) which was used to confirm the structure of the polymer, i.e. the success of the synthesis of PVAC by emulsion polymerization of vinyl-acetate, followed by differential scaning calorimetry (DSC) which gave insight into the thermal properties of PVAC and thermogravimetric analysis (TG) which gave insight into the thermal decomposition of PVAC. Comparing the FT-IR spectrograms of the original and synthesized PVAC, a correlation coefficient of 87.7% was obtained and this value is not big enough to confirm that it is indeed PVAC, but it showed characteristic vibration bands for pure PVAC with a slight deviation, which proves that PVAC has been successfully synthesized. DSC normalized curves confirm the conclusions obtained by FT-IR, but based on values of glass transition. By overlapping the DTG curves, the same conclusion is reached, close results in the decomposition steps confirmed that the synthesis of PVAC by emulsion polymerization of vinyl acetate has been successfully carried out.

Polietilen (PE) jedan je od najjednostavnijih i najpoznatijih polimernih materijala sa širokom primjenom. Linearni polietilen niske gustoće (LLDPE) predstavnik je sintetskog ambalažnog materijala te se najčešće koristi kao ambalaža za pakiranje hrane ili u obliku vrećica. Cilj ovog rada bio je ispitati utjecaj udjela rižinih ljuskica i punila mTiO2 na toplinska svojstva biokompozita linearni polietilen niske gustoće (LLDPE)/rižine ljuskice (RLJ). Rižine ljuskice su nusproizvod nastao preradom riže koji se odvaja od riže tijekom procesa mljevenja te zbog svojih svojstava može imati široku primjenu. Dodatak RLJ u polimernu matricu doprinosi biorazgradnji, maloj težini, žilavosti i otpornosti na vremenske uvjete. Uz rižine ljuskice dodan je i rutil (mTiO2) koji je jedan od najpoznatijih punila zbog svojih izvrsnih svojstva kao što je stabilnost i otpornost pri visokim temperaturama. Biokompoziti LLDPE/RLJ/TiO2 pripremljeni su umješavanjem RLJ u udjelu od 10, 20, 30, 40 i 50 mas % i 5 mas % mTiO2 u čisti LLDPE u Brabender gnjetilici. Utjecaj udjela RLJ i mTiO2 na fazne prijelaze određen je DSC tehnikom dok je toplinska stabilnost ispitana TGA tehnikom u biokompozitima LLDPE/RLJ/TiO2. Na osnovi DSC rezultata dobivenih za LLDPE/RLJ/TiO2 biokompozite promjene u temperaturama taljenja i kristalizacije ukazuju da postoji određeni stupanj interakcija između LLDPE – a, RLJ i mTiO2. TGA rezultati pokazuju bolju toplinsku stabilnost LLDPE – a dodatkom mTiO2. Polyethylene (PE) is one of the simplest and well-known polymeric material with widely used. Linear low-density polyethylene (LLDPE) is a synthetic polymer most commonly used in food packaging or plastic bag production. The aim of this study was to examine the influence of the rice husks content and mTiO2 on the thermal properties of linear low densitiy polyethylene (LLDPE)/rice husks (RH)/TiO2 biocomposite and it can be widely used due to its properties. The incorporation of RH into polymer matrices provides advantageous characteristics, such as biodegradability, light weight, toughness, and resistance to weathering. In addition to rice husks, rutile (mTiO2) was added, which is one of the most famous fillers due to its excellent properties such as stability and resistance to high temperatures. LLDPE/RH/TiO2 biocomposites were prepared by mixing RH in content of 10, 20, 30, 40 and 50 wt % of RH and 5 wt % of mTiO2 in the neat LLDPE in a Brabender mixer. By DSC techniques phase transitions while by TGA technique the thermal stability of the LLDPE/RH/TiO2 biocomposites were obtained with the respect of RH content and addition of mTiO2. According to DSC results for LLDPE/RH/TiO2 biocomposites changes in the melting (Tm) and crystallisation (Tc) temperature indicated that there was some degree of interaction between LLDPE, RH and mTiO2. The TGA results show that the LLDPE is more thermally stable with addition of mTiO2.

U ovome radu pripravljeno je osam različitih uzoraka od kojih prva četiri predstavljaju čisti PEO različitih molekulskih masa (100 000, 300 000, 1·10 6 i 5·10 6 ) a druga četiri predstavljaju kompozite kojima je dodano 5% nanočestica kloro fenil hepta izobutil poliedarskog oligomernog silseskvioksana (PEO/kloro f,hib-POSS). Uzorci su pripremljeni metodom taljenja u statičkim uvjetima te analizirani metodom diferencijalne pretražne kalorimetrije i infracrvene spektroskopije s Fourierovom transformacijom. Cilj ovog rada bio je odrediti toplinske karakteristike PEO/POSS nanokompozita, istražiti interakcije PEO-a i POSS-a te zaključiti o mogućnosti modifikacije svojstava PEO-a dodatkom kloro f,hib-POSS u cilju smanjivanja kristalne faze PEO-a. Nađeno je da je PEO djelomično kristalni polimer koji pokazuje staklasti prijelaz u temperaturnom području od -60 do -50 °C i talište u temperaturnom području od 55-95 °C. Najveći udio kristalne faze ima PEO molekulske mase 100 000 i iznosi 70 %, dok ostali PEO-i molekulske mase 300 000, 1·10 6 i 5·10 6 imaju od 60 – 65 % kristalne faze. Navedenim metodama istraživanja nisu potvrđene interakcije polimera i nanočestica. Izostanak interakcija PEO-a i kloro f,hib POSS nanočestica najvjerojatnije je posljedica loše dispergiranosti nanočestica u polimernoj matrici. Naime, kod priprave nanokompozita metodom taljenja u statičkim uvjetima može doći do aglomeracije nanočestica te se dobije obični kompozit, a ne nanokompozit. In this thesis, eight different samples were prepared, the first four represent pure PEO of different molecular weights (100 000, 300 000, 1·10 6 , 5·10 6 ) and the other four represent composites to which 5% nanoparticles of chloro phenyl hepta isobutyl polyhedral oligomeric silsesquioxane (PEO/chloro f,hib-POSS) were added. Samples were prepared by the melting method in the static conditions and analyzed by differential scanning calorimetry and FT-IR spectroscopy. The aim of this study was to determine the thermal characteristics of PEO/POSS nanocomposites, to investigate the interactions of PEO and POSS and to conclude about the possibilities of modifying the properties of PEO by adding chloro f,hib-POSS in order to reduce the crystal phase of PEO. PEO was found to be a partially crystalline polymer showing glass transition in the temperature range of -60 °C to -50 °C and a melting in the temperature range of 55-95 °C. The largest crystalline phase has a PEO of molecular mass of 100 000 and it is 70% while other PEOs have from 60 to 65% of the crystalline phase. The applied methods did not confirm the interactions between polymers and nanoparticles. The absence of interactions of PEO and chloro f,hib-POSS nanoparticles is most likely due to poor dispersion of nanoparticles in the polymer matrix. During the preparation of nanocomposites by the melting method in static conditions, agglomeration of nanoparticles can occur and the result is regular composite, not a nanocomposite.

U ovom radu istraživan je utjecaj poli(etilen-glikol) poliedarskog oligomernog silseskvioksana (PEG POSS) i aminopropil hepta izobutil poliedarskog oligomernog silseskvioksana (APHIB POSS) na temperature faznih prijalaza, udio kristalne faze i toplinsku stabilnost poli(etilen-oksida). U tu svrhu pripravljene su pastile PEO-a modificirane dodatkom 5 % i 10 % PEG POSS-a, odnosno APHIB POSS-a metodom taljenja u statičkim uvjetima. Nađeno je da se dodatkom modifikatora taljenje i kristalizacija odvijaju u nešto užem temperaturnom području, a udio kristalne faze smanjuje se za 2 – 5 %. Dinamičkom termogravimetrijom utvrđeno je da se PEO i PEO/PEG POSS razgrađuju u jednom razgradnom stupnju u temperaturnom području od 330 do 450 °C. PEO/APHIB POSS razgrađuju se u dva razgradnja stupnja. Prvi razgradni stupanj odgovara razgradnji nanopunila dok se drugi pripisuje razgradnji PEO-a. Dodatak POSS-a ne utječe na temperaturu početka razgradnje PEO-a. In this work, the effect of poly(ethylene glycol) polyhedral oligomeric silsesquioxane (PEG POSS) and aminopropyl hepta isobutil polyhedral oligomeric silsesquioxane (APHIB POSS) on phase transition temperatures, crystallinity and thermal stability of poly(ethylene-oxide) was investigated. Samples of PEO modified by addition of 5 % and 10 % of PEG POSS and APHIB POSS respectively, were prepared by melting method in static conditions. It was found that addition of POSS narrows melting and crystallization region and decreases crystallinity of PEO for 2-5%. By dynamic thermogravimetry was found that PEO and PEO/PEG POSS decompose in one decomposition step in temperature region from 330 to 450 °C. PEO/APHIB POSS decompose in two decomposition steps. First step corresponds to nanoparticles degradation while the second step corresponds to PEO degradation. Addition of POSS does not affect on the onset degradation temperature of PEO.

Svrha ovog rada je promotriti utjecaj pulsirajućeg UV svjetla na modelnu kulturu Lactobacillus plantarum L73 upakiranu u PP/Ac/PVDC i PPmet/PE ambalažu pri različitim udaljenostima uzorka (1,9, 4,65, 7,23, 9,75 i 13,65 cm) te vremenima tretiranja (5, 15, 30 i 60 sekundi). Nakon tretmana je provedena diferencijalna motridbena kalorimetrija kako bi se utvrdile potencijalne promjene barijernih svojstava oba ambalažna materijala. Rezultati istraživanja pokazuju da dolazi do potpune inaktivacije bakterije L. plantarum L73 ukoliko je pakirana u PP/Ac/PVDC ambalažu, dok PPmet/PE ambalaža onemogućava redukciju bakterije zbog nepropusnosti UV zračenja. DSC analiza je pokazala da djelovanjem pulsirajućeg svjetla nije došlo do promjene u strukturi niti jednog ambalažnog materijala. The purpose of this study is to examine the effect of pulsed UV light on Lactobacillus plantarum L73 packaged in PP/Ac/PVDC and PPmet/PE at different distances of the sample (1,9, 4,65, 7,23, 9,75 i 13,65 cm) and treatment times (5, 15, 30 i 60 seconds). Differential scanning calorimetry was done after the treatment to determine potential changes of barrier properties of both packaging. Research results show that complete inactivation of L. Plantarum L73 was achieved if the bacteria was packaged in PP/Ac/PVDC, while PPmet/PE packaging disables reduction of the bacteria because it's impermeable to UV light. DSC analysis showed that pulsed UV light didn't cause changes in the structure of neither of the packaging materials.

Study explored high voltage electrical discharge (HVED) for recovery of bioactive compounds from Dalmatian sage. HVED parameters were: treatment time (3, 9 min), ethanol content (0, 25, 50%, v/v), voltage for argon (15, 20 kV) and nitrogen (20, 25 kV). Findings were compared to conventional extraction (CE) with assessment of total phenolic content (TPC), antioxidant activity (EPR), NIR spectroscopy, colorimetric parameters, Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Raw sage was analyzed for pesticide residues and heavy metals. The optimal HVED extraction expressed as TPC 57.21 mg GAE/g was obtained with nitrogen/9 min/25 kV/33% of ethanol. Sage is safe for extraction in terms of pesticide residues and heavy metals. HVED electroporation facilitated the extraction of bioactive compounds and produced extracts with high antioxidant potential, thus confirmed HVED as “green” extraction for sustainable functional food production.

Svrha ovog rada bila je pripremiti uzorke mješavina PLA/PEO te utvrditi mješljivost temeljem istraživanja interakcija PLA-a s PEO-om u mješavinama različitih sastava. Mješavine PLA/PEO različitih sastava pripremljene su na laboratorijskom ekstruderu pri čemu tijekom ekstrudiranja nije došlo do toplinske razgradnje. Diferencijalna pretražna kalorimetrija, DSC, primijenjena je za određivanje karakterističnih prijelaza čistih polimera i njihovih mješavina, s ciljem utvrđivanja mješljivosti komponenata u mješavini. Staklište PLA, kao kriterij za procjenu mješljivosti, nije bilo moguće odrediti zbog preklapanja s endotermnim pikom taljenja PEO-a. Stoga su tališta čistih polimera promatrana kao kriterij mješljivosti. Na temelju dobivenih rezultata može se zaključiti da su mješavine PLA/PEO djelomično mješljive, odnosno samo pri većem udjelu jedne (80/20) ili druge komponente u mješavini (20/80). Primjenom infracrvene spektroskopije s Fourierovom transformacijom, FTIR, potvrđeno je postojanje interakcija u mješavinama PLA/PEO. Najznačajniji pomaci karakterističnih vrpci uočeni su samo u mješavinama s većim udjelom jedne (80/20) ili druge komponente u mješavini (20/80). The purpose of this study was to prepare PLA/PEO blends and determine miscibility based on PLA interaction with PEO in blends of different composition. Blends of PLA/PEO of different compositions were prepared on the laboratory extruder without thermal degradation. Differential scanning calorimetry, DSC, was applied to determine the characteristic transitions of pure polymers and their blends in order to determine the miscibility of the components in the blend. Evaluation of miscibility with glass transition metod could not be applied to the PLA/PEO blend because the melting endothermic of PEO and the glass transition of PLA, T g of PLA, were overlapped. In these cases, the melting temperature, T m depression method can be used. From these results it can be concluded that PLA/PEO blends are partially miscible, or only in the higher proportion of one (80/20) or other component in the blend (20/80). Infrared Fourier transform spectroscopy, FTIR, confirmed the existence of interactions in the PLA/PEO blends. The most significant shifts of characteristic bands were observed only in blends with a higher proportion of one (80/20) or other component in the blend (20/80).

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.

Istražena je uloga aminokiselina R295 i M367 za stabilnost enzima auksin-amidohidrolaze BrILL2 iz kineskog kupusa (Brassica rapa L.). U tu svrhu korišteni su konstrukti R295A i M367A prethodno dobiveni mjesno-specifičnom mutagenezom. Rekombinantni proteini, divlji tip i mutirane varijante, su proizvedeni heterolognom ekspresijom u bakteriji Escherichia coli, pročišćeni afinitetnom kromatografijom pomoću Ni-NTA agaroze i provjereni elektroforezom u poliakrilamidnom gelu. Modeliranjem je predložen model, odnosno tercijarna struktura divljeg tipa BrILL2, a kao predložak korištena je auksin-amidohidrolaza iz Arabidopsis thaliana. Aminokiseline R295 i M367 stvaraju međusobnu interakciju u blizini aktivnog mjesta koja potpomaže postizanju stabilnije zatvorene konformacije enzima. Njihova mutacija u alanin dovodi do perturbacija u sekundarnoj strukturi mutiranih varijanata u odnosu na divlji tip što je dokazano metodom cirkularnog dikroizma. Diferencijalnom pretražnom kalorimetrijom pokazano je da promjene u sekundarnoj strukturi uzrokovane mutacijama utječu na stabilnost enzima. The role of amino acids R295and M367was investigated for the stability of auxin-amidohydrolase BrILL2 from Chinese cabbage (Brassica rapa L.).Constructs R295A and M367A,previously prepared by site specific mutagenesis, were used. The recombinant proteins were produced by heterologous expression in Escherichia coli bacteria, purified by affinity chromatography using Ni-NTA agarose resin and confirmed by electrophoresis in polyacrylamide gel. Tertiary structure of wild type BrILL2 was modeled on the basis of auxin-amidohydrolase from Arabidopsis thaliana. Amino acids R295 and M367 interact in the proximity of the active site and this interaction participate in stabilization of closed conformation..Their mutation to alanine results in the perturbation of secondary structure of the mutants in comparison to the wild type which was proven by circular dichroism.Differential scanning calorimetry determined that the change of secondary structure affects the stability of the enzyme.

Tijekom prerade kompozitnog materijala sastavljenog od aluminijske folije oplemenjene laminiranim poliolefinskim troslojem nastaju defekti poliolefinskog trosloja kao posljedica stvaranja gela koji uvelike smanjuju kvalitetu dobivenog proizvoda. Samim time dovode do značajnih proizvodnih gubitaka jer su, uz vizualna, narušena i barijerna svojstva materijala. Navedeni kompozitni materijal se dobiva laminiranjem triju koekstrudiranih slojeva poliolefina na aluminijsku foliju. Uzroci nastajanja gela mogu biti različite prirode, kao što su neadekvatni ishodni materijali, nestručno rukovanje i skladištenje ili pak neprimjereni procesni uvjeti preradbe zbog čega nastaju i različite vrste gelova. U ovom radu provedena je toplinska analiza uzoraka poliolefinskih materijala, nastalih defekata te samog kompozitnog materijala termogravimetrijskom analizom i diferencijalnom pretražnom kalorimetrijom. Također, provedena je FTIR spektroskopska analiza. Temeljem dobivenih podataka određena je vrsta nastalog gela. The emphasis of this work is investigation of defects due to the gel formation on the surface of composite material consisting of aluminium foil laminated with three layered polyolefinic film. Such defects lead to significant manufacturing losses and the visual and barrier properties of material are being disturbed as well. Mentioned composite is being manufactured by laminating of three different coextruded polyolefinic layers on aluminium foils surface. Gels forming causes are different as formed gels can vary in nature due to the usage of inadequate start materials, incompetent operation and storage or unsuitable process conditions. Thermal analysis of used polyolefinic materials as well as formed defects and composite material was performed applying thermogravimetric analysis and differential scanning calorimetry. In addition, FTIR spectroscopic analysis was performed. Concerning the obtained results, type of formed gels was determined.

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.

Polimeri danas predstavljaju skupinu materijala koji pronalaze vrlo širok raspon primjene. Njihov razvoj i neka buduća primjena nisu mogući bez karakterizacije. Između ostalih, toplinske karakteristike materijala predstavljaju glavne čimbenike za njegovu buduću specifičnu primjenu. U ovom radu je dan kratki pregled toplinskih metoda analize, s posebnom primjenom na polimerne materijale. Poseban naglasak je na 4 toplinske metode. To su termogravimetrijska analiza (TGA), razlikovna pretražna kalorimetrija (DSC), termomehanička analiza (TMA) i dinamičko-mehanička analiza (DMA). Za svaku od ove 4 tehnike ukratko je opisan princip rada instrumentacije, navedene su osnovne korisne informacije koje je moguće dobiti upotrebom pojedine tehnike, te teorijske osnove nužne za razumijevanje dobivenih rezultata. Za svaku od metoda također su navedeni i neki općeniti primjeri dobivenih rezultata te objašnjenja istih. Polymers are a group of materials which finds huge range of applications in nowadays. But their development and future applications are not possible without their characterization. Among others, thermal characteristics of material are maybe crucial for their application. This work gives short overview of methods for material’s thermal analysis, especially for polymers. Four methods are elaborated, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), thermomechanical analysis (TMA) and dynamic mechanical analysis (DMA). For each of these four methods short principle of work is given, main useful information which is possible to receive using these methods are listed too. Also, general theory of each method for better understanding and some common method results’ examples are given.

Five novel anhydrous catanionic dodecylsulfates containing multi-charged and multi-tailed quaternary ammonium centers were synthesized and examined with light microscopy, differential scanning calorimetry and X-ray powder diffraction. This study is an attempt to explain the relationship between chemical structure, resulting molecular architecture, phase transition energetics, and intermolecular interactions of the individual amphiphiles that ultimately lead to mesomorphic product. All examined compounds are of typical layered structure at room temperature. The dimeric didodecylsulfate crystallizes in monoclinic, while trimeric tridodecylsulfate in triclinic crystal system, as obtained by X-ray powder diffraction. The long spacing, d/Å, decreases linearly with the increase of the ionic head number, and of n-dodecyl chain number. The thermal analysis of the samples indicates rich thermal behavior with thermotropic mesomorphism and polymorphism for all examined catanionics, as well as isotropisation accompanied by decomposition for three-headed and three-tailed dodecylsulfates. Their thermal behavior is greatly promoted by the quaternary ammonium centers. Examined catanionics show thermotropic phases over a broader temperature range due to the ability to accommodate chain disorder and strong ionic interactions. Maltese crosses, oily streaks textures, stepped drops and fan-shaped textures affirmed the existence of various smectic mesophases.

U radu je ispitana mogućnost utvrđivanja patvorenja meda poznatog botaničkog podrijetla pomoću diferencijalne motridbene kalorimetrije (DMK, engl. DSC). Uzorci monoflornih vrsta meda - bagrema, kadulje i kestena, i livade kao poliflorne vrste meda podvrgnuti su analizi kemijskog sastava, mjerenju boje, određivanju reoloških parametara, a proučavano je i njihovo termičko ponašanje pri niskim i visokim temperaturama. DMK krivulje poslužile su za dobivanje uvida u ponašanje ispitivanih vrsta meda u širokom temperaturnom području (od -100 do 220 °C), odnosno kao osnova za određivanje početne i srednje temperature staklastog prijelaza (Tg), promjene specifičnog toplinskog kapaciteta (cp) te izračunavanje entalpije taljenja (Hm). Odabranim uzorcima meda je u određenim udjelima (5, 10 i 20 %) dodan fruktozni sirup (kao moguće sredstvo za patvorenje meda) kako bi se ispitao utjecaj dodatka sirupa na termičko ponašanje različitih vrsta meda, odnosno da bi se istražilo kod koje količine sirupa je moguće utvrditi patvorenje meda. Obrada rezultata termičke analize pokazala je statistički značajnu razliku između nepatvorenog uzorka i patvorenih uzoraka meda kod svih udjela sirupa. Dodatak sirupa od 5 do 20 % je rezultirao u promjeni početne (engl. onset) i srednje (engl. midpoint) temperature staklastog prijelaza patvorenih uzoraka meda (snižavanje Tg vrijednosti) i u porastu vrijednosti entalpije taljenja. Promjena specifičnog toplinskog kapaciteta se nije pokazala dobrim parametrom za utvrđivanje prisutnosti sirupa. Mjerenje boje i određivanje reoloških svojstava patvorenih uzoraka meda poslužili su kao dodatne metode za utvrđivanje patvorenja meda. In this work, differential scanning calorimetry (DSC) has been used for detection of adulteration in Croatian honeys of familiar botanical origin. Samples of monofloral honeys (acacia, sage, chestnut) and meadow, as a polifloral honey type, have been subjected to chemical analysis, colour measurement, determination of rheological parameters, as well as determination of thermal behaviour. DSC scans were used to determine behaviour of honey types under study in a very broad temperature range (from -100 to 220 °C), i.e. as a base for determining onset and midpoint glass transition temperatures (Tg), change of specific heat capacity (cp) and enthalpy of melting (Hm). The effect of syrup addition (at 5, 10 and 20 %) in honey samples and detection of honey adulteration was investigated. Results of thermal analysis showed statistically significant difference between authentic and adulterated honeys. Adulteration of the honeys with 5-20 % fructose syrup addition caused changes in both Tg (decreasing Tg values) and Hm (increasing Hm values). The variation of the specific heat capacity (cp) did not appear to be good parameter for detection of added syrup, as a possible honey adulterant. Measurements of colour and rheological properties determination of adulterated honey samples served as additional methods for detection of honey adulteration.