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Poly(vinyl alcohol)-based nanocomposites consisting of shaped TiO2 nanocrystals (nanoparticles, nanotubes or nanorods) were synthesized by direct blending of the polymer and a solution of titania nanocrystals or powder. In order to elucidate the influence of the shape of the titania nanocrystals on thermal stability of the polymer matrix and particles interaction with poly(vinyl alcohol) (PVA) chains, structural and thermal characterizations of PVA/TiO2 nanocomposites were performed. Faceted nanoparticles increased the thermal stability of the PVA matrix. Titania nanotubes and nanorods did not show any stabilizing effect on the polymer matrix under an argon atmosphere. The thermo-oxidative degradation temperature of PVA increased with addition of faceted TiO2 nanoparticles. The thermo-oxidative stability of the PVA matrix was affected more by the presence of titania nanotubes and nanorods in comparison with its thermal stability under an inert atmosphere. The degree crystallinity (X-c=32 %) of the PVA matrix slightly decreased in the presence of the faceted TiO2 nanoparticles in nanocomposite samples.

A series of novel thermoplastic urethane-siloxane copolymers (TPUSs) based on a α,ω-dihydroxy-[poly(ε-caprolactone)-b-poly(dimethylsiloxane)-b- -poly(ε-caprolactone)] (α,ω-dihydroxy-PCL-PDMS-PCL) triblock copolymer, 4,4'-methylenediphenyl diisocyanate (MDI) and 1,4-butanediol (BD) was synthesized. The effects of the content (9-63 mass %) of hard urethane segments and their degree of polymerization on the properties of the segmented TPUSs were investigated. The structure, composition and hard segment degree of polymerization of the hard segments were examined using 1H- and quantitative 13C-NMR spectroscopy. The degree of crystallinity of the synthesized copolymers was determined using wide-angle X-ray scattering (WAXS). The surface properties were evaluated by measuring the water contact angle and water absorption. In the series of the TPUSs, the average degree of polymerization of the hard segments was varied from 1.2 to 14.4 MDI-BD units. It was found that average values from 3.8 to 14.4 MDI-BD units were effective segment lengths for crystallization of hard segments, which resulted in an increase in the degree of microphase separation of the copolymers. Spherulite-like superstructures were observed in copolymer films by scanning electron microscopy (SEM), which are believed to arise from the crystallization of the hard segments and/or PCL segments, depending on the content of the hard segments. The surface of the copolymers became more hydrophobic with increasing weight fraction of PDMS. The synthesized copolymers based on a PCL-PDMS-PCL segment showed good thermal stability, which increased with increasing content of soft PDMS segments, as was confirmed by the value of the starting temperature of thermal degradation., U ovom radu prikazana je struktura i neka svojstva serije novih termoplastičnih uretan-siloksanskih kopolimera (TPUSs) na bazi α,ω-dihidroksi-[poli(ε-kaprolakton)-b-poli(dimetilsiloksan)-b-poli(ε-kaprolakton)] triblok kopolimera (α,ω-dihidroksi-PCL-PDMS-PCL), 4,4'-metilendifenildiizocijanata (MDI) i 1,4-butandiola (BD). Ispitan je uticaj sadržaja uretanskog tvrdog segmenta (9-63 mas. %) i njegove dužine, tj. stepena polimerizacije, izražene preko broja MDI-BD ostataka, na svojstva segmentiranih TPUSs. Struktura, sastav i stepen polimerizacije tvrdog segmenta su ispitani pomoću 1H- i kvantitativne 13C-NMR spektroskopije. Stepen kristaliničnosti kopolimera je određen metodom difrakcije X-zraka na velikim uglovima (WAXS). Površinska svojstva kopolimera su ispitana određivanjem kontaktnih uglova sa vodom i merenjem apsorpcije vode. U seriji kopolimera dužina tvrdog segmenta izražena preko broja ponavljajućih MDI-BD jedinica je varirana od 1,2 do 14,4. Utvrđeno je da tvrdi segmenti sa 3,8 do 14,4 ponavljajućih MDI-BD jedinica efikasno kristališu, što je rezultovalo u povećanju stepena mikrofazne separacije kopolimera. SEM analiza je pokazala prisustvo sferulitne strukture u kopolimernim filmovima, koja najverovatnije potiče od kristalizacije tvrdih i/ili PCL segmenata, zavisno od sadržaja tvrdih segmenata. Hidrofobnost površine kopolimera je rasla sa povećanjem masenog udela PDMS-a u odgovarajućem uzorku. Sintetisani poliuretani na bazi PCL-PDMS-PCL pokazuju povećanje termičke stabilnosti sa povećanjem sadržaja mekih PDMS segmenata, što je potvrđeno porastom početne temperature degradacije, određene TG analizom.

A series of novel thermoplastic urethane-siloxane copolymers (TPUSs) based on a alpha,omega-dihydroxy-[poly(epsilon-caprolactone)-b-poly(dimethylsiloxane)-b-poly(epsilon-caprolactone)] (alpha,omega-dihydroxy-PCL-PDMS-PCL) triblock. copolymer, 4,4-methylenediphenyl diisocyanate (MDI) and 1,4-butanediol (BD) was synthesized. The effects of the content (9-63 mass %) of hard urethane segments and their degree of polymerization on the properties of the segmented TPUSs were investigated. The structure, composition and hard segment degree of polymerization of the hard segments were examined using (1)H- and quantitative (13)C-NMR spectroscopy. The degree of crystallinity of the synthesized copolymers was determined using wide-angle X-ray scattering (WAXS). The surface properties were evaluated by measuring the water contact angle and water absorption. In the series of the TPUSs, the average degree of polymerization of the hard segments was varied from 1.2 to 14.4 MDI-BD units. It was found that average values from 3.8 to 14.4 MDI-BD units were effective segment lengths for crystallization of hard segments, which resulted in an increase in the degree of microphase separation of the copolymers. Spherulite-like superstructures were observed in copolymer films by scanning electron microscopy (SEM), which are believed to arise from the crystallization of the hard segments and/or PCL segments, depending on the content of the hard segments. The surface of the copolymers became more hydrophobic with increasing weight fraction of PDMS. The synthesized copolymers based on a PCL-PDMS-PCL segment showed good thermal stability, which increased with increasing content of soft PDMS segments, as was confirmed by the value of the starting temperature of thermal degradation.

The dependence of the Mooney scorch time and cure index on the blend ratio of chlorosulphonated polyethylene/natural rubber (CSM/SMR 20 CV) and chlorosulphonated polyethylene/chlorinated natural rubber (CSM/Pergut S 40) blends were determined in the temperature range from 120 C to 160 C using a Monsanto Mooney viscometer. Semi-efficient vulcanization systems were used for the study. The morphology of the fracture surface of the crosslinked systems was determined by Scanning Electron Microscopy (SEM). The results showed that the scorch time decreased with increasing SMR 20 CV and Pergut S 40 contents. This observation is attributed to the increasing solubility of sulfur, as the content of SMR 20 CV and Pergut S 40 in the composition increased. For temperatures greater than 140 C, the dependence of the scorch time on blend ratios diminishes, as enough thermal energy is available to overcome the activation energy of vulcanization. The differing curing characteristics of the two blends is explained by the compatibility factor of the respective blend. Morphological analysis of the blends shows a very satisfactory agreement.

Acrylonitrile-butadiene rubber (NBR), polychloroprene rubber (CR). chlorosulphonated polyethylene rubber (CSM) and their blends were cross-linked with sulphur, ethylene-thiourea. magnesium oxide or their combination. The effect of nano- and micro- particle sized of 35 pphr SiO2 on the thermostability and surface morphology of all the crosslinked systems,vas investigated. Identification of the structure of nano- and micro- particle sized SiO2 filled NBR/CSM and CR/CSM crosslinked systems was carried out by Fourier transform infrared spectroscopy (FTIR) with an attenuated total reflectance (ATR) extension. The thermal stability of the nano- and micro- particle sized SiO2 filled NBR/CSM and CR/CSM crosslinked systems were carried out by thermogravimetric analysis (TGA). The glass transition temperature (T-g) of the samples was determined by differential Scanning calorimetry (DSC). The morphology of the fracture surface of the crosslinked systems was carried out by scanning electron microscope (SEM). The results show when filled with nano-particle sized of SiO2 NBR/CSM and CR/CSM polymer matrix have a strong peak from SiO-C at 1079 cm(-1). This suggests the an interaction between the SiO2, which should lead to an increased thermal stability, higher values of T-g, better dispersion the nano-SiO2 and more polish, without cracks than micro-filled NBR/CSM and CR/CSM crosslinked systems.