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 bonding between organic polymer and inorganic network, two types of silane coupling agent (vinyl trimethoxysilane and 3-(trimethoxysilyl)propyl methacrylate) were used to introduce specific interactions and to control phase behaviour in the interface between polymer and silica. The interfacial interactions between polymer and inorganic segment in the presence of silane have been investigated by Fourier transform infrared spectroscopy. Thermogravimetric analysis shows that the thermal stability of organic components in the hybrids is enhanced by addition of silane coupling agents. Scanning electron micrographs reveal that silica particles are homogeneously dispersed in the organic matrix as a result of the specific interactions