Influence of structural factors on degradation product formation: Primary pyrolysis products of poly(acyl sulfides) investigated by direct pyrolysis mass spectrometry

Thermal degradation of two poly(acyl sulfide) polymers, poly(adipoyl sulfide) (PADS) and poly(terephthaloyl sulfide) (PTS) was investigated by direct pyrolysis mass spectrometry (DPMS). The structures of pyrolysis products detected in the DPMS analysis of both PADS and PTS indicate that the thermal degradation takes place mainly through a loss of carbon monoxide and carbonyl oxysulfide leading to the formation of cyclics. In the case of PADS, linear products with thioacid end groups were formed through hydrogen transfer reactions. In the case of PTS, almost equal proportions of linear products with phenyl end groups and cyclic products were formed. The mechanism of formation of degradation products has also been addressed.