Kinetics of polymerization of oligovinylsiloxanes

Abstract Taking oligomethylvinyldimethylsiloxane as an example the kinetics of polymerization of oligovinylsiloxanes in the temperature interval of 150–200° in the presence of various amounts of initiator (dicumyl peroxide), have been studied by infrared spectroscopy and gravimetric analysis (extraction in a Soxhlet apparatus). An equation for the rate of polymerization is derived and the initial and maximal polymerization rates, the limiting degree of conversion, the energy of activation for polymerization and other variables have been determined. It was found that the polymerization rate varies little with variation in the quantity of initiator but it increases sharply as the temperature is raised or when an active comonomer, namely the polyester TGM-3, is added.