PVC-Silica Sol-gel Hybrids: Effect of Interphase Bonding by Aminopropyltrimethoxysilane on Thermal and Mechanical Properties

摘要

Two types of hybrid materials from Polyvinyl chloride) (PVC) using different amounts of silica have been prepared by the sol-gel technique. The hybrids without inter-phase bonding were prepared by the in-situ generation of silica network from tetraethoxysilane (TEOS) in the PVC matrix. The inter-phase bonding in the hybrid material was achieved by the reaction of aminopropyltrimethoxysilane (APTMOS) with the PVC chain and then carrying out sol-gel process in presence of TEOS. Morphology of the silica particles produced in-situ in the hybrid films was studied by Scanning Electron Microscopy. The inter-phase bonding considerably reduced the silica particle size making their distribution more uniform in the matrix as compared to the unbonded hybrids. Dynamical mechanical thermal analysis was carried out to measure the glass transition temperature from the maxima of tan S curves. The storage modulus and the glass transition temperature of the resulting hybrids were found to increase whereas the thermal coefficient of expansion was considerably reduced with the inclusion of aminosilane in the sol-gel hybrids.