Composite materials based on polyurethane with fragments of poly(vinyl butyral-vinyl acetate-vinyl alcohol) copolymer in their structure filled with silver- and copper-containing silica

A series of polymeric composites based on polyurethanes with copolymer fragments of poly(vinyl butyral-vinyl acetate-vinyl alcohol) and 1,6-hexamethylenediamine filled with modified precipitated silica were synthesized. The content of silver in the nanocomposites was 0.1–0.2 and of copper – 0.14 and 0.2 mmol per 1 g of SiO2 (02AgCu; AgCu and 01Ag samples). The content of silver-containing silica filler in the polymer composites was 0.1, 0.5 and 1.0 wt. %. By means of the IR spectroscopy, it has been found that a physical immobilization of modified silica in the polymeric matrix takes place due to the presence of intermolecular hydrogen bonds. The influence of fillers on the structure and properties of polymer materials, in particular, on thermophysical properties and physico-mechanical parameters (tensile strength and relative elongation at rupture), were investigated. The results of physico-mechanical tests indicate that the strength characteristics of polyurethane depend on the content and concentration of fillers. It has been found that the polymeric sample filled with 02AgCu nanocomposite (0.2 mmol of Ag and Cu per 1 g of SiO2) has the highest strength of the rupture. It has been shown that the introduction of modified silica leads to a reduction of relative elongation at rupture of polymeric nanocomposite. The highest values showed the sample filled with AgCu (0.1 and 0.12 mmol Ag and Cu, respectively, per 1 g of SiO2). The introduction of silver-containing silica nanocomposites into a polyurethane, containing polyvinylbutiral copolymer fragments, leads to an increase in tensile strength and reduction of relative elongation at rupture. Polymeric composite with 0.5 wt. % of filler had the highest values of physico-mechanical parameters. It has been shown that the thermosphysical characteristics depend on the concentration and composition of the fillers and have a nonlinear character. The synthesized nanocomposites can be effectively used as biomedical materials.