Thermokinetic Studies in the Polycarbosilane–Oligosilazane–Rolivsan System

Abstract

Curing and pyrolysis of ceramic-forming systems based on polycarbosilane, oligovinylsilazane, and Rolivsan® were studied by differential scanning calorimetry, thermal gravimetric analysis, and IR spectroscopy. Mechanisms of three-step curing were suggested. The kinetics of curing, occurring without weight changes, was described assuming that the conversion rate is proportional to the thermal flux. In the case of pyrolysis accompanied by the weight loss, the conversion rate was assumed to be proportional to the weight loss rate. Based on the kinetic models obtained, heat treatment conditions were suggested to ensure uniform progress of curing and pyrolysis.