Dynamic mechanical and thermogravimetric analyses of the effect of ferric oxide on the thermaloxidative degradation of silicone rubber

Abstract

The thermaloxidative degradation of hydrosilation formed dimethylsiloxane rubber networks containing ferric oxide in amounts of 0 to 60% (w/w) was investigated by dynamic mechanical analysis (DMA) and thermogravimetry (TG). Scanning work showed that the key weight loss event from TG and the key stiffening event on DMA correlated, showing maximum temperatures at 40% ferric oxide content. Isothermal work showed TG and DMA to be of a very complementary nature. Under isothermal decomposition three chemistry regions were identified-one dominated by thermal decomposition, one dominated by oxidative crosslinking, and a transition region. From Arrhenius kinetics, apparent activation energies, pre-exponential factors, and rate constants were calculated. © 1990.