Role of silane coupling agents for performance improvement of poly(vinyl acetate)/tetraethyl orthosilicate hybrid composites prepared by a sol-gel process

Silica based poly(vinyl acetate)/inorganic hybrid composites were prepared via a sol-gel process under acidic conditions. Because the phase behaviour of the hybrids is greatly affected by weak interactions such as hydrogen bo nding between organic polymer and inorganic network, two types of silane co upling agent (vinyl trimethoxysilane and 3-(trimethoxysilyl)propyl methacry late) were used to introduce specific interactions and to control phase beh aviour in the interface between polymer and silica. The interfacial interac tions between polymer and inorganic segment in the presence of silane have been investigated by Fourier transform infrared spectroscopy. Thermogravime tric analysis shows that the thermal stability of organic components in the hybrids is enhanced by addition of silane coupling agents. Scanning electr on micrographs reveal that silica particles are homogeneously dispersed in the organic matrix as a result of the specific interactions. (C) 2001 Socie ty of Chemical Industry.