EFFECT OF CATALYST ON IN-SITU SILICA REINFORCEMENT OF STYRENE-BUTADIENE RUBBER VULCANIZATE BY THE SOL-GEL REACTION OF TETRAETHOXYSILANE

In situ silica reinforcement of styrene-butadiene rubber (SBR) vulcani zate has been achieved by the sol-gel reaction of tetraethoxysilane (T EOS) using n-butylamine as a catalyst. SBR was vulcanized with sulfur and soaked in TEOS and in an aqueous solution of the catalyst. When hy drochloric acid was used as a catalyst for the sol-gel reaction, silic a particles were not introduced into the SBR matrix in this study. The increase of the dynamic modulus and tensile strength at break was con sidered to be due to the interaction between the rubber and the in sit u silica filler in the SBR vulcanizate.