Mechanistic Differences in Degradation of Polystyrene and Polystyrene‐Clay Nanocomposite: Thermal and Thermo‐Oxidative Degradation

Summary: A conceptual model for degradation of polymer‐clay brushes is discussed. The model predicts enhancement of inter‐molecular reactions and slowing down of molecular mobility. A polystyrene (PS)‐clay brush system is experimentally compared with virgin PS under the conditions of thermal and thermo‐oxidative degradation. GC‐MS and TGA‐FTIR analysis of the gas phase degradation products of PS‐clay composite confirm a dramatic increase in the yield of inter‐molecular reaction product, such as α‐methylstyrene. Combining DSC measurements with FTIR analysis of condensed phase thermo‐oxidative degradation of PS‐clay suggests that PS‐clay nanocomposite is more stable to oxidation, however, oxidation products tend to accumulate in it because of slowing down diffusion of oxidation products. Gas phase IR spectra from the TGA‐FTIR study of virgin PS and PS‐clay for different stages of degradation. magnified image Gas phase IR spectra from the TGA‐FTIR study of virgin PS and PS‐clay for different stages of degradation.