Abstract. Flame-retardant polymer composites based on homo-or copolymers of propylene as the matrix polymer and dispersed magnesium hydroxide, surface-modified by polyperoxides, as the filler have been obtained and characterized. The influence of the polyperoxide nature and the content of peroxide groups immobilized at the filler surface onto the mechanical and rheological properties as well as flame retardancy of composites have been studied. The peroxide surface modification of magnesium hydroxide results both in more even distribution of inorganic particles in the polymer matrix and strong interaction at the filler-polymer interface that in turn provides an appreciable improvement in the composite physico-mechanical properties.

Combining two different novel techniques, namely Bgrafting from^polymerization and in situ sol-gel synthesis, nanocomposites based on CdS nanocrystals embedded into thin polymer films with diverse structure (either poly(acrylic acid) (PAA) homopolymer or mosaic one composed of polystyrene (PS) and PAA chains) grafted to the solid surface have been obtained. The structure of grafted polymer films as well as the composition of obtained on their basis nanocomposite films were studied and characterized by UV-visible spectroscopy, IR-spectroscopy, scanning electron microscopy, and atomic-force microscopy. Two fractions of CdS nanocrystals with the sizes of~4.5-4.7 and~5.7-6.0 nm formed in polymer films of both types have been found. It has been revealed that the content ratio of these two fractions mostly depends on the structure of polymer films.

Методом полімеризаційного наповнення синтезовано структуровані нанокомпозитні гідрогелі на основі поліакриламіду та попередньо модифікованих реакційноздатними полімерами мінеральних наночастинок гідроксиапатиту, ZnO, ТіО 2 . Показано, що фізикомеханічні характеристики отриманих нанокомпозитів значною мірою визначаються природою модифікатора мінеральних наночастинок. Досліджено вплив природи мінерального наповнювача та реакційноздатного модифікатора поверхні наночастинок на колоїднохімічні та фізико-механічні властивості нанокомпозитних гідрогелів. Отримані гідрогелі характеризуються достатньо високими фізико-механічними властивостями. Ключові слова: структуровані гідрогелі, реакційноздатні кополімери, радикальна кополімеризація, нанокомпозити, мінеральні наночастинки.

Structural combining of polymer hydrogel network with mineral nanoparticles (metals, oxides, salts) is a very promising approach to create new functional materials with the specific properties. In this study, the cross-linked polymer hydrogels with embedded cadmium sulphide nanocrystals have been synthesized via radical copolymerization of acryl amide with acrylic acid or 2-(dimethylamino)ethyl methacrylate and N,N′-methylenebis(acrylamide) as cross-linker in aqueous media in the presence of nanoparticle precursor-cadmium salt, followed by subjecting the hydrogel obtained to gaseous hydrogen sulphide; this provides the in situ formation of CdS nanocrystals in pores of the hydrogel polymeric network. The effect of the Cd 2+ cation concentration on the copolymerization kinetics, as well as on the gel-fraction content has been studied. The formation of CdS nanocrystals with the size of 3-6 nm has been proved by UV-vis spectroscopy and X-Ray diffractometry. Importantly, the nanocrystal size is largely determined by the density of the hydrogel polymer network. The compressive strain of hydrogels with CdS nanoparticles is significantly larger than that for the initial hydrogels containing Cd 2+ cations only, apparently owing to the breaking of ionic and coordination bonds between metal cations and polar functional groups of matrix copolymer, which provide additional cross-linking of the hydrogel matrix. The obtained nanocomposite hydrogels are highly elastic materials characterized by a sufficiently high strength.

Cross-linked polymeric and nanocomposite films based on poly(2-ethyl-2-oxazoline) and modified mineral nanoparticles of hydroxyapatite and silica have been obtained via radical cross- linking initiated by peroxide containing reactive copolymers. The influence of temperature and additional cross-linking agents on the peculiarities of curing process has been studied. The obtained results reveal that at high temperatures the dependence of film gel-fraction values on time has the extremal character. Obtained cross-linked nanocomposite films are characterized by improved physico-mechanical properties that depend on the nature of mineral nanoparticles, content of peroxide containing copolymer and on the presence of additional cross-linking agent.