Degradation of Hydrogenated Styrene—Butadiene Rubber at High Temperature

Abstract

Abstract Degradation of hydrogenated styrene—butadiene rubber (HSBR) having different levels of unsaturation has been studied over a wide range of temperatures under anaerobic and aerobic conditions using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), IR and NMR spectroscopy. TGA data indicate higher thermal stability of hydrogenated rubber as compared to SBR in nitrogen, although an anomalous behavior is observed in air due to crosslinking and oxidation of styrene—butadiene rubber (SBR). Isothermal data confirm the above observations. IR and NMR results reveal thermal isomerization, cyclization, oxidation, depolymerization, and chain scission processes. The nature and amount of products formed depend on the time and temperature of degradation and also on the level of hydrogenation of SBR.