Polymerisation and degradation of an aromatic amine-based naphthoxazine

Pyrolysis mass spectrometry (MS) analysis of aromatic amine-based naphthoxazine monomer (15-Na) and Poly15-Na has been carried out. Evaporation and degradation of the monomer are detected during the curing process while the polymerisation proceeded. The polymerisation and degradation mechanisms are proposed for 15-Na and Poly15-Na, respectively. The proposed polymerisation mechanism for naphthoxazine monomer was through the aniline units either by coupling of the radicals generated by cleavage of the side rings or by substitution to the benzene ring of aniline. It has been determined that polymerisation followed opposing paths yielding some thermally less stable linkages through which thermally crosslinked polynaphthoxazine (Poly15-Na) suffers from low thermal stability. It has been shown that pyrolysis MS is a very useful technique to investigate the polymerisation and degradation mechanisms and degradation products of these materials.