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Polyetheretherketone (PEEK) is considered as an excellent biomaterial for bone grafting and connective tissue replacement. The clinical potential is, however, limited by its bioinertness, poor osteoconduction, and weak antibacterial activity. These disadvantages can be overcome by introducing suitable additives to produce mineral-polymer composites or coatings. In this work, a PEEK-based bioactive composite has been obtained by blending the polymer with magnesium phosphate (Mg3(PO4)2) particles in amounts ranging from 1 to 10 wt.% using the hot press technique. The obtained composite exhibited improved mechanical and physical properties, above the lower limits set for bone engineering applications. The tested grafts were found to not induce cytotoxicity. The presence of magnesium phosphate induced the mineralisation process with no adverse effects on the expression of the marker crucial for osteoblastic differentiation. The most promising results were observed in the grafts containing 1 wt.% of magnesium phosphate embedded within the PEEK matrix. The improved bioactivity of grafts, together with suitable physical–chemical and mechanical properties, indicate this composite as a promising orthopaedic implant material.

One-sided surface charred European beech wood (Fagus sylvatica L.) was studied. Radial and tangential specimens of dimensions of 50 x 25 x 350 mm were one-sided surface charred at 200, 250, 300, 350, and 400 degrees C for various times using a contact heating system. Specimens of dimensions of 50 x 25 x 50 mm(3) were prepared for treatment intensity analysis and its effect on surface wettability. Density profiles of the radial and tangential charred specimens were determined using X-ray densitography with a resolution of 0.05 mm. The wettability of the one-sided surface charred wood specimens was analyzed via contact angle, measured using the sessile drop method and determined over 10 to 150 s. The oven-dried specimens were partially submerged in water and water uptake was recorded after 2, 4, 6, 8, 10, 48, and 72 h according to EN-927-5. The surface density of the radial specimen groups charred at 200 degrees C for 6 min and 250 degrees C for 4 min decreased by about 4.5 to 8.2%. With increasingly severe charring, the surface density decreased by about 15.5 to 33.5%. A mild charring process produced a surface charred layer of approx. 2 mm, while higher temperatures and longer times affected the density up to 4-6 mm beneath the surface. Differences were found between the water uptake of the radial and tangential charred beech specimens. The most significant decrease of 56% in water uptake was recorded for the radial group prepared at 200 degrees C for 20 min after floating in water for 72 h. Water uptake in the radial groups modified at 250 degrees C for 4 and 6 min after 72 h decreased by 38% and 36%, respectively. The tangential groups did not show any statistically significant decrease. The average water uptake of the groups charred at 200 degrees C for 20 min, 350 degrees C for 2 min and 400 degrees C for 1 min was greater than that of the reference; the variability of the measured data was significantly greater due to the highly anisotropic character of the tan

The aim of this paper was to analyze selected properties of beech wood (Fagus sylvatica L.) treated by one-sided surface charring. Specimens were one-side charred with a hot plate using several time-temperature combinations (from 200 to 400 degrees C). Characteristics such as colour, discoloration, surface roughness, fire resistance, total carbohydrate content at several wood layers and decay resistance were evaluated. Surface charring was applied to the radial and tangential surfaces. Colour measurements showed that the surface of the wood turned grey due to charring. In addition to colour measurements, other experiments showed significant differences between radial and tangential specimens due to their different structures. The higher the temperature used in treating them, the lower the roughness values for radial specimens, while the trend for tangential specimens was the opposite. A smoother surface is more fire resistant, so radial specimens are generally better in this regard. Tangential specimens are more susceptible during preparation to forming cracks that impair flame resistance because a continuous protective densified layer is not formed. The determination of total carbohydrates revealed significant changes at various wood depths after surface charring. These changes were more predictable in radial specimens due to the annual ring orientation, because each layer consisted of a similar earlywood/latewood ratio. Finally, when decay resistance was assessed, weight loss was found to be lower in all specimens than in the references. The results suggest that charring at a particular combination of temperature and time improved the investigated properties of the surface-modified beech.

One-sided surface charred European beech wood (Fagus sylvatica L.) was studied. Radial and tangential specimens of dimensions of 50 x 25 x 350 mm were one-sided surface charred at 200, 250, 300, 350, and 400 degrees C for various times using a contact heating system. Specimens of dimensions of 50 x 25 x 50 mm(3) were prepared for treatment intensity analysis and its effect on surface wettability. Density profiles of the radial and tangential charred specimens were determined using X-ray densitography with a resolution of 0.05 mm. The wettability of the one-sided surface charred wood specimens was analyzed via contact angle, measured using the sessile drop method and determined over 10 to 150 s. The oven-dried specimens were partially submerged in water and water uptake was recorded after 2, 4, 6, 8, 10, 48, and 72 h according to EN-927-5. The surface density of the radial specimen groups charred at 200 degrees C for 6 min and 250 degrees C for 4 min decreased by about 4.5 to 8.2%. With increasingly severe charring, the surface density decreased by about 15.5 to 33.5%. A mild charring process produced a surface charred layer of approx. 2 mm, while higher temperatures and longer times affected the density up to 4-6 mm beneath the surface. Differences were found between the water uptake of the radial and tangential charred beech specimens. The most significant decrease of 56% in water uptake was recorded for the radial group prepared at 200 degrees C for 20 min after floating in water for 72 h. Water uptake in the radial groups modified at 250 degrees C for 4 and 6 min after 72 h decreased by 38% and 36%, respectively. The tangential groups did not show any statistically significant decrease. The average water uptake of the groups charred at 200 degrees C for 20 min, 350 degrees C for 2 min and 400 degrees C for 1 min was greater than that of the reference; the variability of the measured data was significantly greater due to the highly anisotropic character of the tan

The aim of this paper was to analyze selected properties of beech wood (Fagus sylvatica L.) treated by one-sided surface charring. Specimens were one-side charred with a hot plate using several time-temperature combinations (from 200 to 400 degrees C). Characteristics such as colour, discoloration, surface roughness, fire resistance, total carbohydrate content at several wood layers and decay resistance were evaluated. Surface charring was applied to the radial and tangential surfaces. Colour measurements showed that the surface of the wood turned grey due to charring. In addition to colour measurements, other experiments showed significant differences between radial and tangential specimens due to their different structures. The higher the temperature used in treating them, the lower the roughness values for radial specimens, while the trend for tangential specimens was the opposite. A smoother surface is more fire resistant, so radial specimens are generally better in this regard. Tangential specimens are more susceptible during preparation to forming cracks that impair flame resistance because a continuous protective densified layer is not formed. The determination of total carbohydrates revealed significant changes at various wood depths after surface charring. These changes were more predictable in radial specimens due to the annual ring orientation, because each layer consisted of a similar earlywood/latewood ratio. Finally, when decay resistance was assessed, weight loss was found to be lower in all specimens than in the references. The results suggest that charring at a particular combination of temperature and time improved the investigated properties of the surface-modified beech.

One-sided surface charred European beech wood (Fagus sylvatica L.) was studied. Radial and tangential specimens of dimensions of 50 x 25 x 350 mm were one-sided surface charred at 200, 250, 300, 350, and 400 degrees C for various times using a contact heating system. Specimens of dimensions of 50 x 25 x 50 mm(3) were prepared for treatment intensity analysis and its effect on surface wettability. Density profiles of the radial and tangential charred specimens were determined using X-ray densitography with a resolution of 0.05 mm. The wettability of the one-sided surface charred wood specimens was analyzed via contact angle, measured using the sessile drop method and determined over 10 to 150 s. The oven-dried specimens were partially submerged in water and water uptake was recorded after 2, 4, 6, 8, 10, 48, and 72 h according to EN-927-5. The surface density of the radial specimen groups charred at 200 degrees C for 6 min and 250 degrees C for 4 min decreased by about 4.5 to 8.2%. With increasingly severe charring, the surface density decreased by about 15.5 to 33.5%. A mild charring process produced a surface charred layer of approx. 2 mm, while higher temperatures and longer times affected the density up to 4-6 mm beneath the surface. Differences were found between the water uptake of the radial and tangential charred beech specimens. The most significant decrease of 56% in water uptake was recorded for the radial group prepared at 200 degrees C for 20 min after floating in water for 72 h. Water uptake in the radial groups modified at 250 degrees C for 4 and 6 min after 72 h decreased by 38% and 36%, respectively. The tangential groups did not show any statistically significant decrease. The average water uptake of the groups charred at 200 degrees C for 20 min, 350 degrees C for 2 min and 400 degrees C for 1 min was greater than that of the reference; the variability of the measured data was significantly greater due to the highly anisotropic character of the tan

One-sided surface charred European beech wood (Fagus sylvatica L.) was studied. Radial and tangential specimens of dimensions of 50 x 25 x 350 mm were one-sided surface charred at 200, 250, 300, 350, and 400 degrees C for various times using a contact heating system. Specimens of dimensions of 50 x 25 x 50 mm(3) were prepared for treatment intensity analysis and its effect on surface wettability. Density profiles of the radial and tangential charred specimens were determined using X-ray densitography with a resolution of 0.05 mm. The wettability of the one-sided surface charred wood specimens was analyzed via contact angle, measured using the sessile drop method and determined over 10 to 150 s. The oven-dried specimens were partially submerged in water and water uptake was recorded after 2, 4, 6, 8, 10, 48, and 72 h according to EN-927-5. The surface density of the radial specimen groups charred at 200 degrees C for 6 min and 250 degrees C for 4 min decreased by about 4.5 to 8.2%. With increasingly severe charring, the surface density decreased by about 15.5 to 33.5%. A mild charring process produced a surface charred layer of approx. 2 mm, while higher temperatures and longer times affected the density up to 4-6 mm beneath the surface. Differences were found between the water uptake of the radial and tangential charred beech specimens. The most significant decrease of 56% in water uptake was recorded for the radial group prepared at 200 degrees C for 20 min after floating in water for 72 h. Water uptake in the radial groups modified at 250 degrees C for 4 and 6 min after 72 h decreased by 38% and 36%, respectively. The tangential groups did not show any statistically significant decrease. The average water uptake of the groups charred at 200 degrees C for 20 min, 350 degrees C for 2 min and 400 degrees C for 1 min was greater than that of the reference; the variability of the measured data was significantly greater due to the highly anisotropic character of the tan, info:eu-repo/semantics/openAccess

One-sided surface charred European beech wood (Fagus sylvatica L.) was studied. Radial and tangential specimens of dimensions of 50 x 25 x 350 mm were one-sided surface charred at 200, 250, 300, 350, and 400 degrees C for various times using a contact heating system. Specimens of dimensions of 50 x 25 x 50 mm(3) were prepared for treatment intensity analysis and its effect on surface wettability. Density profiles of the radial and tangential charred specimens were determined using X-ray densitography with a resolution of 0.05 mm. The wettability of the one-sided surface charred wood specimens was analyzed via contact angle, measured using the sessile drop method and determined over 10 to 150 s. The oven-dried specimens were partially submerged in water and water uptake was recorded after 2, 4, 6, 8, 10, 48, and 72 h according to EN-927-5. The surface density of the radial specimen groups charred at 200 degrees C for 6 min and 250 degrees C for 4 min decreased by about 4.5 to 8.2%. With increasingly severe charring, the surface density decreased by about 15.5 to 33.5%. A mild charring process produced a surface charred layer of approx. 2 mm, while higher temperatures and longer times affected the density up to 4-6 mm beneath the surface. Differences were found between the water uptake of the radial and tangential charred beech specimens. The most significant decrease of 56% in water uptake was recorded for the radial group prepared at 200 degrees C for 20 min after floating in water for 72 h. Water uptake in the radial groups modified at 250 degrees C for 4 and 6 min after 72 h decreased by 38% and 36%, respectively. The tangential groups did not show any statistically significant decrease. The average water uptake of the groups charred at 200 degrees C for 20 min, 350 degrees C for 2 min and 400 degrees C for 1 min was greater than that of the reference; the variability of the measured data was significantly greater due to the highly anisotropic character of the tan, info:eu-repo/semantics/openAccess

One-sided surface charred European beech wood (Fagus sylvatica L.) was studied. Radial and tangential specimens of dimensions of 50 x 25 x 350 mm were one-sided surface charred at 200, 250, 300, 350, and 400 degrees C for various times using a contact heating system. Specimens of dimensions of 50 x 25 x 50 mm(3) were prepared for treatment intensity analysis and its effect on surface wettability. Density profiles of the radial and tangential charred specimens were determined using X-ray densitography with a resolution of 0.05 mm. The wettability of the one-sided surface charred wood specimens was analyzed via contact angle, measured using the sessile drop method and determined over 10 to 150 s. The oven-dried specimens were partially submerged in water and water uptake was recorded after 2, 4, 6, 8, 10, 48, and 72 h according to EN-927-5. The surface density of the radial specimen groups charred at 200 degrees C for 6 min and 250 degrees C for 4 min decreased by about 4.5 to 8.2%. With increasingly severe charring, the surface density decreased by about 15.5 to 33.5%. A mild charring process produced a surface charred layer of approx. 2 mm, while higher temperatures and longer times affected the density up to 4-6 mm beneath the surface. Differences were found between the water uptake of the radial and tangential charred beech specimens. The most significant decrease of 56% in water uptake was recorded for the radial group prepared at 200 degrees C for 20 min after floating in water for 72 h. Water uptake in the radial groups modified at 250 degrees C for 4 and 6 min after 72 h decreased by 38% and 36%, respectively. The tangential groups did not show any statistically significant decrease. The average water uptake of the groups charred at 200 degrees C for 20 min, 350 degrees C for 2 min and 400 degrees C for 1 min was greater than that of the reference; the variability of the measured data was significantly greater due to the highly anisotropic character of the tan, info:eu-repo/semantics/openAccess

Součástí této diplomové práce je literární rešerše zabývající se přípravou vodou ředitelných polymerních disperzí pomocí emulzní polymerace, výčtem metod stanovení molekulové hmotnosti polymerů s důrazem na stanovení molekulové hmotnosti emulzních polymerů pomocí gelové permeační chromatografie s více úhlovým detektorem rozptylu světla, zejména pak na metodu frakcionace tokem v asymetrickém tokovém poli spolu s více úhlovým detektorem rozptylu světla. V experimentální části je popsána příprava akrylátových latexů a hodnocení jejich základních vlastností, molekulové hmotnost a její distribuce. Z latexů, u kterých byl předpoklad použitelnosti v lakařství, byly vytvořeny nátěrové povlaky a sledovány u nich byly fyzikálně-mechanické vlastnosti, chemická odolnost a citlivost vůči působení vody. Výsledky a diskuse se týkají především porovnání chemických a fyzikálních vlivů působících na molekulovou hmotnost a mass recovery (výtěžnost) při separaci metodou frakcionace tokem v asymetrickém tokovém poli. Bylo zjištěno, že separace a tudíž i stanovení molekulové hmotnosti mohou být významně zkresleny při analýze akrylátových latexových polymerů majících vysokou molekulovou hmotnost (polymery s vysokým podílem butylakrylátu jako komonomeru) a zároveň obsahujících vyšší koncentraci ionizovaných karboxylových skupin (alkalizované kopolymery s obsahem od 2 3 hm % kyseliny methakrylové ve výchozí násadě akrylátových monomerů)., This master thesis includes research dealing with water-borne polymeric dispersions prepared by emulsion polymerization, a summary of methods for determining the molecular weight of polymers, with emphasis on determining the molecular weight of emulsion polymers using gel permeation chromatography with multi-angle light scattering detector, especially asymmetric flow field-flow fractionation together with a multi-angle light scattering detector. The experimental part describes the preparation of acrylate latexes and the evaluation of their basic properties: solids content, pH, viscosity, particle size, zeta potential, glass transition temperature and molar mass distribution. Coating films were cast from the latexes, which were expected to be useful in painting, to monitor physical-mechanical properties, chemical resistance and sensitivity to water. The results and discussion mainly concern the comparison of chemical and physical influences causing a change of molecular weight and mass recovery during separation by the method asymmetric flow field-flow fractionation. It has been found that separation and thus determining the molecular weight may be significantly distorted during analysis of acrylic latex polymers, which have a high molecular weight (polymers with a high proportion of butyl acrylate as a comonomer), and also containing higher concentrations of ionized carboxyl groups (alkalized copolymers containing from 2-3 % methacrylic acid in the starting batch of acrylate monomers)., Fakulta chemicko-technologická, Diplomantka přednesla výsledky své diplomové práce a zodpověděla dotazy členů komise., Dokončená práce s úspěšnou obhajobou

Rigid polyurethane (PUR) foams are widely used as heat insulation material in construction industry or for electronic appliances manufacturing. After finishing their life-time, it is necessary to eliminate foam wastes. The aim of this study was to prepare a pair of industrial PUR adhesives of medium viscosity containing recycled rigid PUR foam. Three methods of milling were tested: knife-milling, two-roll milling, and ball-milling. Only two-roll milling gives the PUR micro-powder usable for following adhesives modification. The micro-powder was used as passive filler in PUR adhesives and potential reactivity for polyol pack replacement was studied. Hydroxyl and amine numbers were determined in mixture with virgin polyol. One-component PUR prepolymer adhesive was prepared using various dosages of the micro powder and the tensile strength of bound wood was measured. As additional parameters, also free film adhesive mechanical parameters were tested and particle size distribution of the micro powder was analyzed. Two adhesive formulations were prepared for independent evaluation of the micro powder reactivity. The results showed growing of the mechanical strength of wood bonding with growing dosage of the micro powder., Tvrdé polyurethanové (PUR) pěny jsou často používány jako tepelně izolační materiál ve stavebnictví nebo při výrobě elektronických zařízení. Po skončení životnosti výrobků je nutné odstranit odpady z těchto pěn. Cílem této studie bylo připravit dvojici průmyslových PUR lepidel střední viskozity obsahujících recyklovanou mikromletou tuhou PUR pěnu. Byly testovány tři způsoby jemného mletí: nožovým mlýnem, dvouválcovým mlýnem a kulovým mlýnem. Pouze dvouválcový mlýn poskytuje mikromletý PUR prach použitelný pro následné modifikace lepidel. Mikroprášek byl použit jako pasivní plnivo v PUR lepidlech a byla také studována potenciální chemická reaktivita umožňující náhradu polyolové složky lepidel. Byla stanovena hydroxylová a aminová čísla recyklátu ve směsi s panenským polyolem. Následně bylo připraveno jednosložkové PUR prepolymerní lepidlo za použití různých dávek mikroprášku a změřena pevnost v tahu lepeného spoje dřeva. Rovněž byly testovány mechanické vlastnosti volného filmu lepidla a analyzována distribuce velikosti částic mikroprášku. Pro nezávislé vyhodnocení reaktivity mikromletého PUR prášku byly připraveny dvě formulace lepidel. Výsledky ukázaly růst mechanické pevnosti lepení dřeva s rostoucí dávkou mikromletého prášku.

Předložená práce se zabývá přípravou hybridní anexové membrány, která spočívá v povrchové modifikaci komerčně dostupné polyethersulfonové (PES) membrány. Jedná se o kovalentně vázanou vrstvu obsahující kopolymer poly(styren-co-divinylbenzen-co-4-vinylbenzylchlorid), která zlepšuje elektrochemické vlastnosti PES membrány. Připravené anexové membrány byly testovány pomocí stanovení iontovýměnné kapacity, specifického odporu, permselektivity. Studium morfologie připravených membrán bylo provedeno pomocí SEM analýzy a FT- IR spektroskopie. Připravené membrány mají potenciál ve využití např. v elektrodialyzačních procesech., This paper deals with the preparation of hybrid anion-exchange membrane which consists in the surface modification of commercially polyethersulfonic (PES) membrane . It is a covalently bonded layer comprising poly (styrene-co-divinylbenzene-co-4-vinylbenzyl chloride) copolymer which improves the electro-chemical properties of the PES membrane. The prepared anion-exchange membranes were tested by determining ion-exchange capacity, specific resistance, permselectivity. Study of morphology of prepared membranes was performed by SEM analysis and FT-IR spectroscopy. The prepared membranes have potential in use for example in electrodialysis processes.

Předložená disertační práce se zabývá tématikou fosfazenů s jejich následným využitím jako retardérů hoření a zároveň tvrdidel pro reaktoplasty. Teoretická část je zaměřena na fosfazeny, jejich historii, zejména na hexachloro-cyklo-trifosfazen, jeho vlastnosti a syntézu. V další části je věnována kapitola epoxidovým pryskyřicím, jejich přípravě a vytvrzování. V poslední části je rešerše zaměřena na retardéry hoření, na využití derivátů hexachloro-cyklo-trifosfazenu jako vytvrzujících látek a zároveň retardérů hoření pro epoxidové pryskyřice, které jsou využívány v průmyslu. V experimentální části disertační práce je první část věnována syntézám derivátů hexachloro-cyklo-trifosfazenu, další část poté kapitole vytvrzování vybrané epoxidové pryskyřice pomocí připravených derivátů hexachloro-cyklo-trifosfazenu a vybraným aminem pro porovnání vlastností, který se běžně jako tvrdidlo pro epoxidové pryskyřice používá. Jsou zde shrnuty použité metody charakterizace a sledován vliv použitých derivátů hexachloro-cyklo-trifosfazenu na retardaci hoření. Cílem předložené disertační práce byla syntéza nových derivátů hexachloro-cyklo-trifosfazenu a jejich využití jako tvrdidel např. pro epoxidové pryskyřice a zároveň retardérů hoření., The presented dissertation deals with the topic of phosphazenes with their subsequent use as flame retardants and curing agents for the thermosets. The theoretical part is focused on phosphazenes, their history, hexachloro-cyclo-triphosphazene, its properties and synthesis. The next part is devoted to epoxy resins, their preparation and curing. In the last part, the search was focused on flame retardants, the use of hexachloro-cyclo-triphosphazene derivatives as curing agents and flame retardants for bisphenol type epoxy resins, which have been commonly used in industry. In the experimental part of the dissertation, the part is devoted to the synthesis of hexachloro-cyclo-triphosphazene derivatives, the curing of the selected epoxy resin with the prepared hexachloro-cyclo-triphosphazene derivatives and the comparison of the selected amine which is commonly used as a hardener for epoxy resins. It summarizes the methods used for characterization and the influence with respect using derivatives hexachloro-cyclo-triphosphazene to fire retardancy. The aim of this dissertation was the synthesis of new hexachloro-cyclo-triphosphazene derivatives used as both fire retardants and hardeners for epoxy resins., Fakulta chemicko-technologická

The electrospinning of flurescent probe polyamide 6 doped by 7H-benzimidazo[2,1-a]benzo[de]isoquinolin-7-on is presented as a model processing photoluminescent nanofibers. The presence of the fluorescent probe in the fiber layers was confirmed by Attenuated total reflection - Fourier transform infrared spectroscopy (ATR - FTIR); the surface nanofiber structure was described by high-resulution fluorescence microscope and scanning electron microscope images. The prepared nanofibers with the fluorescent label was further characterized by fluorescence spectroscopy, both in the solid phase and in the solution., Zvlákňování fluorescenční značky polyamidu 6 dopovaného 7H-benzimidazo [2,1-a] benzo [de] isochinolin-7-onem je prezentováno jako model fotoluminiscenčních nanovláken. Přítomnost fluorescenční značky ve vláknových vrstvách byla potvrzena infračervenou spektroskopií (ATR - FTIR); povrchová struktura nanovláken byla popsána fluorescenčním mikroskopem s vysokým rozlišením a pomocí skenovacího elektronového mikroskopu. Připravená nanovlákna s fluorescenční značkou byla dále charakterizována fluorescenční spektroskopií jak v pevné fázi, tak v roztoku.

The paper deals with a novel flame retardant and its application in waterborne coatings. The flame retardant was synthesized from hexachloro-cyclo-triphosphazene by nucleophilic substitution with allyl amine. Functionalized emulsion copolymers bearing in the structure hexaallylamino-cyclo-triphosphazene were prepared by the semi-continuous emulsion polymerization. The latexes were used as the main component of transparent coating systems cured by melamine-formaldehyde resin. The incorporation hexaallylamino-cyclo-triphosphazene did not affect transparency, flexibility and toughness of resulting coatings and increased their flame stability., Práce se zabývá syntézou a využitím nového retardéru hoření a jeho využitím ve vodou ředitelných nátěrech. Retardér hoření byl syntetizován z hexachloro-cyklo-trifisfazenu nukleofilní substitucí s allylaminem. Pomocí semi-kontunuální emulzní polymerace byly připraveny funkcionalizované emulzní kopolymery nesoucí ve své struktuře hexaallylamino-cyklo-trifosfazen. Tyto latexy byly využity jako hlavní součást transparentních nátěrových systémů vytvrzovaných melaminoformaldehydovou pryskyřicí. Vnesení hexaallylamino-cyklo-trifosfazenu neovlivnilo transparentnost, flexibilitu ani houževnatost výsledných nátěrů a zvýšilo jejich tepelnou stabilitu.

In this study, self-crosslinking core-shell latexes comprising copolymerized perfluorethyl groups and a novel flame retardant based on phosphazene derivative were prepared by the semi-continuous emulsion polymerization. The heterogeneous cation-exchange membranes were obtained by dispersing commercial strong acid cation-exchange resin powder in the latex binder and casting the mixture. It was found that the increased concentration of fluorine atoms and phosphazene units in the macromolecular structure of interfacially crosslinked emulsion polymers resulted in a significant enhancement of their flame resistance and shape stability in aqueous environment. Moreover, the easily prepared heterogeneous cation-exchange membranes based were shown to exhibit satisfactory physicochemical and electrochemical properties., V této práci byly pomocí semi-kontinuální emulzní polymerace připraveny samosíťující core-shell latexy obsahující kopolymerované perfluorethylové skupiny a nový retardér hoření na bázi derivátu fosfazenu. Heterogenní kation-výměnnéh membrány byly připraveny dispergací komerční silně kyselé kation-výměnné pryskyřice v latexovém pojivu a odlitím výsledné směsi.Bylo zjištěno, že zvýšená koncentrace flourových atomů a jednotek fosfazenu v makromolekulární struktuře zesítěných emulzních polymerů způsobila výrazné zvýšení jejich odolnosti vůči hoření a tvarové stálosti ve vodném prostředí. Navíc se ukázalo, že tyto snadno připravitelné heterogenní kation-výměnné membrány vykazují dobré fyzikálně-chemické a elektrochemické vlastnosti.

In this study the synthesis of a novel flame retardant based on halogenophosphazene derivative and its application in waterborne coatings based on self-crosslinking latexes was investigated. Hexaallylamino-cyclo-triphosphazene was synthesized by nucleophilic substitution of hexachloro-cyclo-triphosphazene with allyl amine. Latexes of functionalized core-shell particles bearing in the structure hexaallylamino-cyclo-triphosphazene molecules were prepared by emulsion polymerization of methyl methacrylate, butyl acrylate and methacrylic acid as main monomers., V této práci byla studována syntéza nového retardéru hoření na bázi derivátu halogenofosfazenu a jeho využití ve vodouředitelných nátěrech založených na samosíťujících latexech. Hexaallylamino-cyklo-trifosfazen byl syntetizován nuklofilní substitucí hexachloro-cyklo-trifosfazenu s allylaminem. Latexy tvořené funkcionalizovanými core-shell částicemi nesoucími ve své struktuře molekuly hexaallylamino-cyklo-trifosfazenu byly připraveny emulzní polymerací methylmethakrylátu, butylakrylátu a kyseliny methakrylové jako hlavních monomerů.

In this study, the spinnability of styrene-ethyl acrylate copolymers prepared via emulsion polymerization was explored with the aim to establish the influence of glass transition temperature and polymer composition on morphological features of electrospun materials with regard to their hydrophobic/hydrophilic nature. Nonwoven mats from polymer solutions in N,N-dimethylformamide were spun using the electrospinning method (Nanospider device). It was demonstrated that changing the copolymer polarity and glass transition temperature by copolymer composition or utilizing different supporting materials might lead to nanofiber webs with controlled hydrophobic/hydrophilic properties, which predetermines them for a wide range of applications such as protective textiles, composites, etc., V této práci bylo zkoumáno zvlákňování kopolymerů na bázi styren-ethylakrylátu připravených emulzní polymerací s cílem popsat vliv teploty skelného přechodu a polymerního složení na morfologii zvlákněných materiálů s ohledem na jejich hydrofobní/hydrofilní povahu. Z roztoků polymeru v N,N´-dimethylformamidu byly připraveny netkané textilie pomocí zvlákňovací metody (NanospiderTM device). Ukázalo se, že změnou polarity a teploty skelného přechodu vlivem složení kopolymeru nebo použitím různých podkladových materiálů mohou být připraveny nanovlákenné materiály s řízenou hydrofobicitou/hydrofilitou.

In this contribution the application of a novel flame retardant based on halogenophosphazene derivative in waterborne coatings based on self-crosslinking latexes was investigated. Hexaallylamino-cyclo-triphosphazene was synthesized by nucleophilic substitution of hexachloro-cyclo-triphosphazene with allyl amine. Latexes of functionalized core-shell particles bearing in the structure a covalently linked hexachloro-cyclo-triphosphazene were prepared by the semi-continuous non-seeded emulsion polymerization of methyl methacrylate, butyl acrylate and methacrylic acid as main monomers. For interfacial crosslinking, diacetone acrylamide was copolymerized into the shell layer of latex particles to provide sites for subsequent reaction with adipic acid dihydrazide. The incorporation hexaallylamino-cyclo-triphosphazene did not affect transparency, flexibility, toughness and adhesive properties of resulting coatings. Moreover, the presence of the novel flame retardant increased the flame stability of coatings., Tento příspěvek pojednává o využití nového retardéru hoření na bázi derivátu halogenofosfazenu ve vodouředitelných nátěrech založených na samosíťujících latexech. Hexaalllyamino-cyklo-trifosfazen byl syntetizován nukleofilní substitucí hexachloro-cyklo-trifosfazenu allylaminem. Semikontinuální emulzní polymerací methylmethakrylátu, butylakrylátu a kyseliny methakrylové byly připraveny latexy tvořené funkcionalizovanými core-shell částicemi nesoucími kovalentně zapojený hexachloro-cyklo-trifosfazen. Diacetonakrylamid byl kopolymerován v obalové vrstvě latexových částic, aby byla zajištěna reaktivní místa pro post-síťování pomocí dihydrazidu kyseliny adipové. Zabudování hexaalllyamino-cyklo-trifosfazenu neovlivnilo transparentnost, pružnost, houževnatost ani adhezní vlastnosti výsledných nátěrů. Přítomnost nového retardéru hoření navíc zvýšila tepelnou odolnost nátěrů.

Práce popisuje vývoj transparentních jednosložkových nátěrových systémů tvořených core-shell akrylovými vodnými disperzemi připravenými technikou emulzní polymerace. Latexy na bázi funkcionalizovaných core-shell částic nesoucích ve své struktuře kovalentně navázaný hexachloro-cyklo-trifosfazen byly připraveny semi-kontinuální emulzní polymerací methylmethakrylátu, butylakrylátu and a kyseliny methakrylové jako hlavních monomerů. Diacetonakrylamid byl kopolymerován v obalové vrstvě latexových částic, aby byla zajištěna reaktivní místa pro post-síťování pomocí dihydrazidu kyseliny adipové. Přítomnost retardéru hoření zvýšila tepelnou odolnost nátěrů z pohledu celkového uvolněného tepla, množství uvolněného kouře a maximální rychlosti uvolnění tepla, což nasvědčuje pomalejšímu šíření žáru během spalování materiálu., The paper describes the development of transparent one-component coating systems based on the core-shell acrylic aqueous dispersions prepared using emulsion polymerization technique. Latexes of functionalized core-shell particles bearing in the structure a covalently linked hexachloro-cyclo-triphosphazene were prepared by the semi-continuous non-seeded emulsion polymerization of methyl methacrylate, butyl acrylate and methacrylic acid as main monomers. For interfacial crosslinking, diacetone acrylamide was copolymerized into the shell layer of latex particles to provide sites for subsequent reaction with adipic acid dihydrazide. The presence of the flame retardant increased the flame stability of coatings in terms of total heat release, amount of released smoke and maximum average rate of heat emission, which indicates a slower flame spread during the material combustion.

The present work deals with the surface modification of a commercial microfiltration poly(ethersulfone) membrane by graft polymerization technique. Poly(styrene-co-divinylbenzene-co-4-vinylbenzylchloride) surface layer was covalently attached onto the poly(ethersulfone) support layer to improve the membrane electrochemical properties. Followed by amination, a two-layer anion-exchange membrane was prepared. The effect of surface layer treatment using the extraction in various solvents on membrane morphological and electrochemical characteristics was studied. The membranes were tested from the point of view of water content, ion-exchange capacity, specific resistance, permselectivity, FT-IR spectroscopy, and SEM analysis. It was found that the two-layer anion-exchange membranes after the extraction using tetrahydrofuran or toluene exhibited smooth and porous surface layer, which resulted in improved ion-exchange capacity, electrical resistance, and permselectivity of the membranes., Tato práce se týká povrchové modifikace komerční mikrofiltrační membrány na bázi poly(ethersulfonu) pomocí techniky “graft” polymerace. Povrchová vrstva tvořená kopolymerem na bázi styrene divinylbenzenu a 4-vinylbenzylchloridu byla kovalentně navázána na nosič z poly(ethersulfonu) s cílem zlepšit elektrochemické vlastnosti membrán. Membrány byly testovány z hlediska obsahu vody, iontovýměnné kapacity, specifického odporu, permselektivity, FT-IR spektroskopie a SEM analýzy.

The present work deals with the influence of temperature on the ion-exchange capacity of selected ion-exchangers. Technological operations running at elevated temperatures (drying, homogenization) can influence ion-exchange capability of ion-exchangers, which may affect values of the ion-exchange capacity. Several types of anion and cation-exchangers have been chosen for its application in practice. It was shown that the optimum processing temperature for anion and cation-exchange resins is in the range of 101-115 °C., Tato práce se zabývá vlivem teploty na iontovýměnnou kapacitu vybraných iontoměničů. Technologické postupy probíhající za zvýšených teplot mohou ovlivňovat iontovýměnnou schopnost iontoměničů, což může ovlivnit hodnoty iontovýměnné kapacity. Bylo vybráno několik typů komerčně využívaných anion- a kationvýměnných pryskyřic. Ukázalo se, že optimální pracovní teplota je v případě obou typů iontovýměnných pryskyřic mezi 101-115 °C.

V této diplomové práci byly vybrané typy antidegradantů kovalentně navázány na komerčně dostupné polymery, konkrétně na houževnatý polystyren a polyethylen, které jsou ve velkém rozsahu využívány v průmyslu. Za antidegradanty byly zvoleny světelné stabilizátory. U připravených polymerních systémů byla provedena elementární analýza, stanovení molekulových hmotností metodou gelové permeační chromatografie, termická analýza pomocí termogravimetrie a diferenční skenovací kalorimetrie. Připravené systémy byly vystaveny v podobě filmů urychlenému stárnutí v uměle vytvořených podmínkách., In this diploma thesis, selected types of antidegradants were covalently bound to commercially available polymers, namely to high impact polystyrene and polyethylene, which are widely used in industry. As representants of antidegradants, some types of light stabilizers were chosen. In the prepared polymeric systems, elementary analysis, determination of molecular weights by gel permeation chromatography, thermal analysis using thermogravimetry and differential scanning calorimetry were carried out. The prepared systems in the form of films were exposed to accelerated aging (weathering)., Ústav chemie a technologie makromolekulárních látek, Diplomantka přednesla výsledky své diplomové práce a zodpověděla dotazy členů komise., Dokončená práce s úspěšnou obhajobou

Cílem předložené práce bylo testování vybraných komerčně dodávaných miniaturizovaných tištěných tříelektrodových senzorů na modelovém systému enzym-substrát a následně jejich využití pro detekci proteinu ovalbuminu., The main aim of the thesis was testing of selected commercially available miniaturized screen printed sensors on the model system of the enzyme-substrate and their ubsequent use for detection of the protein ovalbumin., Katedra biologických a biochemických věd, 1. Prezentace výsledků diplomové práce 2. Diskuze k posudkům vedoucího a oponenta diplomové práce 3. Diplomantka zodpověděla všechny dotazy a připomínky k DP

Bakalářská práce se zabývá vitamínem D, především v kontextu významu jeho deficience pro rozvoj kardiovaskulárního onemocnění. V práci jsou shrnuty základní poznatky o vitamínu D, jeho struktura, mechanizmus působení, účinky, syntéza a princip stanovení. Dále je pozornost soustředěna na vliv nedostatku vitamínu D na onemocnění kardiovaskulárního systému, především na rozvoj aterosklerózy, hypertenze a městnavého srdečního selhání., The bachelor thesis deals with vitamin D especially in context of meaning to his deficiency for development of cardiovascular disease. In this study are resumed the basic knowledge of vitamin D, his structure, mechanism of activity, effects, synthesis and the principle of assesment. Then the attention is concerned with the influence of the absence of vitamin D on cardiovascular systém?s disease, especially on the development of arterial sclerosis, hypertension and congestive heart failure., Katedra biologických a biochemických věd, Studentka obhájila bakalářskou práci a zodpověděla všechny otázky komise, Dokončená práce s úspěšnou obhajobou