Synthesis and Thermal and Rheological Properties of Polydimethylsiloxanes Modified with Benzoic Acid Fragments

Abstract

4-(Dimethylvinylsilyl)benzoic acid is obtained by organolithium synthesis. Polydimethylsiloxanes containing silicon hydride groups are modified by introducing benzoic acid fragments via the hydrosilylation reaction. The thermal and rheological properties of the copolymers formed are studied. It is found that a rise in the content of benzoic acid results in a shift in the glass-transition temperature to a higher temperature region and the copolymers do not crystallize. Benzoic acid fragments improve the intermolecular interaction of polydimethylsiloxane chains more strongly than the ones of undecenoic acid.