Thermal stability of new sorption materials based on polysiloxanes

Abstract

The thermal stability of the unmodified, aminated, and thiocarbamoylated polysiloxanes has been studied. The siloxane matrix is stable in the temperature range up to 800°C. For the first time, mass spectrom etry has been applied to the analysis of the composition of the gaseous products of thermal decomposition of the studied polysiloxanes. It has been shown that, in the process of thermal decomposition, the terminal func tional groups are detached and oxidized. Water, ammonia, nitrogen, carbon, and sulfur (in the case of thio urea modified sorbent) oxides are formed predominantly. The quantitative removal of functional groups dur ing heating up to 800°C has been confirmed by IR spectroscopy. A mechanism of thermal decomposition of polysiloxane xerogels has been proposed. It has been found that adsorption of platinum increases the thermal stability of the samples.