Bolbukh Y. Silicon hydride groups of silica surface in reactions of hydrosilylation and polymerisation of olefins

Objects: High dispersed fumed silica; modified silicas with the different contents of silicon-hydride (SiH) groups grafted to the surface; 2-hydroxyethylmethacrylate (HEMA); divinyltetramethyldisiloxane; unfilled polymers and filled with silica polymeric compositions on basied on HEMA. The purposed is to establish a role of silica surface silicon-hydride groups during polymerization and structurization in filled polymeric compositions. Methods: IR-spectroscopy, chemical analysis, thermogravimetric analysis, thermomechanical analysis and swelling. Kinetic features and optimum conditions of carrying out of catalytic hydrosilylation process in organosilicon environment and organic vinyl-containing monomers were established. Quantative determination of silicon-hydride grafted on silica surface are developed and advanced. The influence of grafted SiH groups on processes of thermal and initiated by acrylamide complex of cobalt nitrate HEMA polymerisation was studied. The basic directions of influence of the initiator and surface SiH groups on structurization in filled compositions were established. It is shown that during thermal polymerization, depending on SiH groups contents, the modified filler particles structure is formed or destroyed, and presence of the initiator promotes formation of cross-linked structure with rigid polymeric links.