Kinetics of the Formation of Poly(Methyldecylsiloxane) by Hydrosilylation of Poly(Methylhydrosiloxane) and 1-Decene

Abstract

Poly(methylhydrosiloxane) [PMHS], prepared by siloxane equilibration reaction, was used for the hydrosilylation with 1-decene to obtain poly(methyldecylsiloxane) [PMDS]. Pt(0)-1,3- divinyltetramethyldisiloxane complex was used as a catalyst for hydrosilylation reaction. In order to investigate the kinetics of the formation of PMDS, a series of experiments was performed at different reaction temperatures (from 48 to 64 °C) with catalyst concentrations of 7.0 · 10-7 mol of Pt per mol of CH=CH2. All reactions were carried out in bulk, with equimolar amounts of the reacting Si-H and CH=CH2 groups. The course of the reactions was monitored by following the disappearance of the Si-H bands by quantitative infrared spectroscopy. The obtained results show that an induction period occurs at lower reaction temperatures and that the rate of Si-H conversion follows the first-order kinetics.