NOVEL IN SITU SILICA/POLYDIMETHYLSILOXANE NANOCOMPOSITES: FACILE ONE-POT SYNTHESIS AND CHARACTERIZATION

Abstract

Abstract Synthesis of in situ silica/polydimethylsiloxane (PDMS) nanocomposites by using tetraethylorthosilicate (TEOS) as the precursor for silica and octamethylcyclotetrasiloxane for the polymer in presence of base was undertaken. Simultaneous generation of silica and polymer and dispersion of the nanofiller in the polymer have been reported for the first time. Fourier transform infrared spectroscopy was used as a tool to monitor the reaction conditions. The structure–property relationship of in situ silica/PDMS nanocomposites has been highlighted. Transmission electron microscopic studies reveal finest extent of dispersion of the in situ generated nanosilica, which is found to undergo polymorphic modification determined from wide-angle X-ray diffraction. Nanocomposites exhibit huge improvement in mechanical properties (>150% improvement in tensile strength for just 2 phr TEOS-filled sample) and room temperature storage modulus (>460% improvement in storage modulus for 8 phr TEOS-loaded sample). Polymer–filler interaction significantly improves oxidative thermal stability of the nanocomposites.