A cured mono-benzoxazine (PHB-apa) with both acetylene and aldehyde functional groups exhibits excellent heat resistance. The thermal degradation process of this polybenzoxazine was studied in this work. The pyrolysis temperature range and major thermal degradation products were determined by TGA-FTIR analysis. The stepwise-temperature Py-GC/MS was employed to identify the structures and the contents of the pyrolysis products at different temperature stages. Transformation of chemical structures of the polymer bulk during the pyrolysis process was speculated. The results suggest that the concerted reaction of the aldehyde groups and the polymerization of the acetylene groups form special crosslinking structures that can effectively prevent the release of the amines and the phenols.

具有乙炔和醛官能团的固化的单苯并恶嗪（PHB-apa）表现出优异的耐热性。在这项工作中研究了该聚苯并恶嗪的热降解过程。通过TGA-FTIR分析确定热解温度范围和主要的热降解产物。采用逐步温度Py-GC / MS鉴定不同温度阶段热解产物的结构和含量。推测了在热解过程中聚合物本体的化学结构的转变。结果表明，醛基的协同反应和乙炔基的聚合形成了可以有效防止胺和酚释放的特殊交联结构。