<p>Istraživanja u okviru teze imaju za cilj dobijanje polimernih mreža kod kojih se regulacijom sirovinskog sastava i uslova sinteze mogu menjati svojstva siloksanskih materijala u skladu sa krajnjom primenom. Osnovni cilj istraživanja ove teze je razvoj novih postupaka sinteze hibridnih siloksanskih nanokompozita na osnovu različitih prekursora mreža. Takođe, ispitan je i uticaj različitih tipova funkcionalizacije povr&scaron;ina nanopunila silicijum(IV) oksida (sa hidrofobnom i hidrofilnom povr&scaron;inom) na svojstva kompozitnih materijala za specifične namene. Nanokompoziti na osnovu polimernih mreža se uglavnom koriste u onim primenama gde tradicionalne polimerne mreže ne mogu da zadovolje potrebe koje se pred njih stavljaju. Zato je potrebno razviti postupak koji bi omogućio dobijanje materijala na osnovu polimernih mreža sa pobolj&scaron;anim mehaničkim, elastičnim i toplotnim svojstvima. Motivacija je vođena potrebom razvoja novih kompozitnih materijala koji imaju jedinstvena mehanička, toplotna, termomehanička svojstva sa mogućno&scaron;ću da pomognu u re&scaron;avanju problema okoline, kao &scaron;to su problem sa prostorom, sa automobilima, u elektronici i infrastrukturi, i naravno, oni će biti veliki izazov u nauci materijala i industriji.<br />Siloksanske mreže su dobijene od &alpha;, &omega;-divinil poli(dimetilsiloksana) i poli(metil-hidrogen<br />siloksana) u odnosu 60/40; 50/50 i 40/60. Nanokompoziti su sintetisani dodavanjem različitih sadržaja nanopunila silicijum(IV) oksida (1, 2, 5, 10 i 20 mas.%). Za potvrdu pretpostavljenog mehanizma reakcije umrežavanja siloksana kori&scaron;ćena je FTIR spektroskopija. TEM analiza je kori&scaron;ćena za procenu topologije i potvrdila je dobru disperziju punila u polimernom matriksu. Dodavanje nanopunila pobolj&scaron;ava mehanička svojstva dobijenih materijala i povećanje vrednosti prekidne jačine za kompozite sa hidrofobnim silicijum(IV)oksidom je veće u poređenju sa kompozitima sa hidrofilnim punilima, &scaron;to je očekivano zbog bolje kompatibilnosti hidrofobne matrice i hidrofobnih punila. Termogravimetrijska analiza kori&scaron;ćena je za analizu uticaja vrste funkcionalizacije silicijum(IV) oksida na termičku stabilnost siloksanskih elastomernih<br />materijala. Kao &scaron;to se i očekivalo, porast sadržaja nanopunila povećava termičku stabilnost dobijenih hibridnih materijala. Uticaj punila na temperature faznog prelaza siloksanskih materijala analiziran je diferencijalnom skenirajućom kalorimetrijom. Zbog slabije kompatibilnosti hidrofilnog punila i hidrofobne matrice primećeno je smanjenje vrednosti Tm, a najmanja vrednost temperature topljenja primećena je za uzorak sa najvećim udelom hidrofilnog punila.<br />Uticaj nanopunila na mehaničke i termičke karakteristike dobijenih materijala biće detaljno analiziran, pri čemu je potvrđeno pobolj&scaron;anje mehaničkih svojstava siloksanskih elastomera dodatkom nanopunila. U cilju razvoja novih biokompatibilnih materijala i pobolj&scaron;anja svojstava biorazgradivosti siloksanskih materijala biće sintetisani ABA blok kopolimeri koji se sastoje od segmenata poli(dimetilsiloksana) i poli(laktida). Kao makroinicijator za sintezu blok kopolimera kori&scaron;ćen je polidimetilisiloksan, pa je polimerizacija laktida inicirana hidroksilnim grupama siloksana. Poli(laktid) se odlikuje veoma dobrim mehaničkim svojstvima i biorazgradivo&scaron;ću, dok se kopolimerizacijom sa siloksanima utiče na mehanička svojstva kao i na svojstva povr&scaron;ine sintetisanog kopolimera.</p> / <p>Research in the thesis aims to obtain polymeric networks in which the regulation of the raw<br />material composition and the conditions of the synthesis can alter the properties of the silicone<br />materials in accordance with the final application. The main goal of the research of this thesis is<br />the development of new procedures for the synthesis of hybrid silicone nanocomposites based on<br />different precursors. The influence of different types of surface functionalisation of nanofillers<br />(with hydrophobic and hydrophilic functionalised surface) on the properties of composite<br />materials for specific purposes was investigated. Nanocomposites based on polymer networks are<br />mainly used in those applications where traditional polymer networks cannot meet the needs that<br />are expected. It is therefore necessary to develop a process that would enable the production of<br />materials based on polymeric networks with improved mechanical, elastic and thermal properties.<br />Motivation is driven by the need to develop new composite materials that have unique<br />mechanical, thermal, thermo-mechanical properties with the ability to help solve environmental problems, such as space problems, cars, electronics and infrastructure, and of course they will be<br />a challenge in the material science and industry. Siloxane networks were prepared from &alpha;,&omega;-<br />divinyl poly(dimethylsiloxane) and poli(methyl-hydrogen siloxane) with a ratio 60/40; 50/50 and<br />40/60. Nanocomposites were synthesised with the addition of different contents of silica<br />nanofiller (1, 2 5, 10 and 20 wt%). For the confirmation of the presumed mechanism of siloxane<br />crosslinking reaction FTIR spectroscopy was used. TEM analysis was used for topology<br />evaluation and confirmed good dispersion of the fillers into the polymer matrix. Addition of<br />nanofillers increased the mechanical properties of obtained materials and greater increase of the<br />tensile strength for the composites based on hydrophobic silicon(IV)-oxide was assessed,<br />compared with the hydrophilic ones. It was expected due to better compatibility of hydrophobic<br />silicone matrix and hydrophobic filler particles. Thermogravimetric analysis was used for the<br />evaluation of the influence of the types of silicon(IV)oxide functionalisation, on the thermal<br />degradation of elastomeric materials. As it was expected the increases of nanofillers content<br />increased the thermal stability of obtained hybrid materials. The influence of fillers on the phase<br />transition temperatures of siloxanematerials was analysed with the differential scanning<br />calorimetry. Due to the lower compatibility of hydrophilic filler and hydrophobic matrix<br />decreasing of Tm values was observed, and the lowest value of melting temperature was noticed<br />for the sample with the highest loading of hydrophilic filler.<br />In order to develop new biocompatible materials and improve the biodegradability properties of<br />silicone materials, ABA types of block copolymers consisting of segments of<br />poly(dimethylsiloxane) and poly(lactide) was synthesized. As a macroinitiator for the synthesis of<br />the block copolymer, poly(dimethylisiloxane) was used, so the lactide polymerization starts from<br />the hydroxyl groups of siloxanes. Poly(lactide) is characterized by poor mechanical properties<br />and biodegradability, while copolymerization with silicones will affect the mechanical and<br />surface properties of the synthesized copolymer.</p>

<p>U ovom radu vr&scaron;ena su istraživanja u cilju razvoja novih postupaka sinteze za nekoliko vrsta polimernih mreža i hibridnih biopolimernih materijala za specijalne primene. Cilj je bio da se razvije novi postupak sinteze rotaksana na bazi poli(etilen glikola) i &beta;-ciklodekstrina kaoprekursora mreža. Dobijeni prekursori mreža iskori&scaron;ćeni su za sintezu topolo&scaron;kih gelova koji su umreženi preko hidroksilnih grupa ciklodekstrinskih prstena. Analiziran je i uticaj količine umreživača, odnosno gustine umreženja, na svojstva bubrenja. Proučavan je i uticaj nanopunila na svojstva modelnih epoksi mreža na bazi bisfenola A i poli(oksi propilen) diamina. Kao punila kori&scaron;ćene su nanočestice nemodifikovanog i povr&scaron;inski modifikovanog titanijum(IV)oksida (TiO₂). Dinamičko-mehaničkom analizom potvrđen je ojačavajući efekat punila. Razvijen je postupak sinteze poli(D,L-laktida) u mikrotalasnom polju, čime je drastično smanjeno vreme polimerizacije (sa 150 sati na 15 minuta) u odnosu na klasičnu termosintezu. Sintezom poli(laktida) kao i kopolimera poli(laktida) sa biorazgradivim monomerima (na osnovu obnovljivih sirovina) dobijeni su materijali izuzetnih ekolo&scaron;kih svojstava. Poli(laktid) se odlikuje veoma dobrim mehaničkim svojstvima i biorazgradivo&scaron;ću, dok je blok-kopolimerizacijom sa drugim biorazgradivim monomerima vr&scaron;ena sinteza termoplastičnih poliestara. Variranje dužine segmenata je ostvareno sintezom adekvatnih oligomera kao prekursora za kopolimerizaciju. Vr&scaron;eno je projektovanje sirovinskog sastava segmentiranih elastomera kod kojih postojanje mekih i tvrdih segmenata ima za posledicu mikrofaznu separaciju faza &scaron;to u toku eksploatacije utiče na mehanička svojstva i mogućnost III razgradnje. Na taj način dobijeni su elastomerni materijali željenih svojstava. Metodama FTIC i 1H NMR spektroskopijom potvrđena je pretpostavljena struktura segmenata i finalnih termoplastičnih poliestara. Analizom molskih masa poliestara metodama gel propusne hromatografije, viskozimetrije i osmometrije napona pare, potvrđena je izuzetna kontrola reakcija polimerizacije i uspe&scaron;nost primenjenih metoda sinteze. Analiza toplotnih svojstava blok poliestara diferencijalno skenirajućom kalorimetrijom je pokazala da zbog neme&scaron;ljivosti faza, tvrdih i mekih segmenata, finalni blok poliestri mogu da pokažu razlike u temperaturama faznih transformacija u zavisnosti od dužine i udela segmenata. Termogravimetrijskom analizom je potvrđen uticaj dužine segmenata i faznog razdvajanja na toplotna svojstva termoplastičnih poliestara. Očekuje se da će sintetisani materijali biti podesni za primene u inženjerstvu tkiva, a posebno kao materijali za kontrolisano otpu&scaron;tanje lekova.</p> / <p>The primary goal of the work described in this thesis was to develop new methods for the<br />synthesis of polymer networks and hybrid biopolymers for special applications. The purpose was a development of synthesis procedure for the preparation of rotaxane based on poly(ethylene glycol) and &beta;-cyclodextrin, as network precursors. These network precursors were then cross-linked through hydroxy groups on cyclodextrine rings. Polyrotaxanes are intermediary products in the synthesis of topological gels and they are formed by the insertion of the linear polymer chains of poly(ethylene oxide) into the &beta;-CD cavities. In this work polyrotaxanes from acetylated-&beta;-CD and poly(ethylene oxide) were synthesized. The influence of crosslinker contents, and crosslink density on swelling properties was investigated. The influence of synthesis parameters and filler modification on reactions and final properties of organic-inorganic hybrid materials based on epoxy resin and an organically modified titanium(IV)oxide (TiO2) was investigated. Dynamic-mechanical analysis was used to determine reinforcement effect of nanofiller on the epoxy resin properties. The aim of this work was the investigation of microwave irradiation on the polymerization of D,L-lactide. It was found that if heating is carried out in the microwave field polymerization time of D,Llactide rapidly decreases from 150 hours to 15 minutes. Environmentally friendly materials were obtained from poly(lactide) and copolymers of poly(lactide) and monomers based on renewable resources. Poly(lactide) is biocompatible and biodegradable polymer with high stretching and low extension capacities. It has been used for the production of orthopedic fraction fixators and sutures surgery. Poly(lactide) was used for thermoplastic polyester (TPE) synthesis. Most thermoplastic polyesters derive their properties from segmented or block structures which are achieved by alternating hard and soft segments. FT-IR and 1H NMR spectroscopy were confirmed the assumed structure of segments and final thermoplastic polyesters. Since the properties of these materials strongly depend on the degree of phase separation, the influence of the lenghts of soft and hard segment on final properties of obtained TPEs was studied. Analysis of molecular mass of these polyesters by gel permeation chromatography, vapor pressure osmometry and viscozimetric analysis confirmed that good control of polymerization was achieved and that synthesis methods were successful. Thermal properties were characterized by means of differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). Phase separation had strong influences on thermal properties of obtained TPEs. DCS measurements showed that due to poor mixability of hard and soft segments, final block polyesters could have different temperatures of phase transitions depending on the length of the segments. Thermal degradation and the influence of phase separation on thermal stability of segmented thermoplastic polyesters were confirmed by nonisothermal analysis, using thermogravimetric analysis. It is expected that synthesized materials will be suitable for tissue engineering and as drug carriers.</p>

<p>Ovaj rad je imao za cilj , razvoj postupka sinteze polimernih prekursora mreža na bazi<br />obnovljivih sirovina. Razvijen je postupak sinteze poli laktida u rastvoru dihlor metana. Vreme trajanja postupka sinteze je 6 h, a uspe&scaron;nost samog procesa je potvrđena metodama identifikacije i karakterizacije dobijenih polimera PLLA. U ovom radu, za ispitivanja dobijenih polimernih materijala, uzimajući u obzir ideju o krajnjoj nameni, kori&scaron;ćene su sledeće metode: GPC ( Gel Permeation Chromarography) za određivanje raspodele molekulske mase; IR spektrofotometrija, prikazuje vibraciju atomskih, molekulskih ili funkcionaknih grupa; i termička analiza TGA i DSC, za praćenje promena pri kontrolisanom zagrevanju i hlađenju.<br />Jedan od ciljeva rada je bio i da se da pregled postojećih teorija ojačanja elastomera punilima sa nano česticama, i ispita pona&scaron;anje nano-kompozitnih materiajala pod dejstvom visoko energetskog zračenja ( gama zračenja). U eksperimentalnom delu ispitivani su elastomerni materijale na bazi butadienakrilonitrilnog kaučuka (NBR) i hlorsulfonovanog polietilenskog kaučuka (CSM) . Me&scaron;anjem CSM i NBR formiraju se umreženi sistemi, koji se koriste kao prekursori mreža za dobijanje nano-kompozitnih materijala ojačanaih česticama aktivnih punilačađi i silicijum (IV) oksida. Kod tako dobijenih materijala ispitivane su karakteristike pre i posle ozračivanja &gamma; zracima. Dinamičko-mehaničkom analizom potvrđen je ojačavajući efekat punila.</p> / <p> This work was aimed at the development procedure for the synthesis of polymer precursors<br /> network based on renewable raw materials. Developed a procedure for synthesis of poly<br /> lactide in solution, dichloro methane. The duration of the synthesis procedure was 6 h, and<br /> the success of the process was confirmed by the methods of identification and<br /> characterization of the obtained polymer PLLA. In this paper, the investigation obtained<br /> polymer materials, taking into account the idea of final destination, following methods were<br /> used: GPC (gel permeation Chromarography) to determine the distribution of molecular<br /> weight, IR spectrophotometry, showing the vibration of atomic, molecular or funkcionaknih<br /> group, and thermal analysis TGA and DSC, to track changes in a controlled heating and<br /> cooling.<br /> One of the aims of this study was to be given to review of existing theories of reinforcement<br /> fillers elastomer with nano particles, and examine the behavior of nano-composite<br /> materiajala under the influence of high energy radiation (gamma radiation). In the<br /> experimental part of elastomeric materials have been studied on the basis of<br /> butadienakrilonitrilnog rubber (NBR) and chlorosulphonated polyethylene rubber (CSM). CSM NBR mixing and forming the network system, which are used as precursors for a<br /> network of nano-composite particles ojačanaih active fillers-carbon black and silicon (IV)<br /> oxide. With so obtained materials were investigated characteristics before and after<br /> irradiation with &gamma; rays. Dynamic-mechanical analysis confirmed the reinforcing effect of<br /> fillers.</p>