Thermal decomposition investigation on heat-resistant poly (dimethylsilylene ethynylenemethylphenylene-methylenemethylphenyleneethynylene) resins

Thermal decomposition of heat resistant poly(dimethylsilylene ethynylenemethylphenylenemethylenemethyl-phenyleneethynylene) (PSMA) resins has been investigated by TGA, Py-GC-MS, and TGA-MS analysis tech-niques. The decomposition kinetics was studied with Kissinger-Akahira-Sunose method (KAS method). The results show that the decomposition of the cured PSMA resins is obviously influenced by the presence and lo-cations of the side methyl groups on the benzene rings and their decomposed fragments are different. The side methyl groups on benzene rings easily break down, which make the resins decompose at lower decomposition temperatures. The cleavage of the side methyl groups further induces the decomposition of the main chains of the resins and results in low residue yields. The decomposition mechanisms of the cured PSMA resins are suggested.