Study on the thermal degradation behavior of sulfone-containing polybenzoxazines via Py-GC-MS

A stepwise-temperature testing method by Py-GC-MS was applied to study the thermal degradation processes of two polybenzoxazines containing sulfone group. This new method can give lots of information about degradation gas products and the variation of chemical structures in bulk. The results showed that (1) for 4,4′-sulfonylbiphenol/aniline based polybenzoxazine (PBS), the thermal degradation fragments tend to form heterocyclic compounds in bulk phase; (2) for 4,4′-sulfonyldianiline/phenol based polybenzoxazine (PBAS), crosslinked phenol and aniline structures were preferentially produced from the thermal decomposition fragments in bulk phase. Therefore, it means that PBS is more likely to generate thermally stable fused rings like chars in bulk during pyrolysis process. As the result, a deep insight into the pyrolysis process of polybenzoxazines was achieved by this method, which probably provides a new way to study the degradation behavior of other polymers.