综合采用红外光谱（FTIR）、 核磁碳谱 (13C NMR)、 差示扫描量热（DSC）, 热失重测试(TGA)等多种表征手段, 研究了聚硅芳炔（PAR）和聚硅乙炔（PMR）两种含硅炔基树脂的固化行为, 讨论了树脂固化物的结构与热稳定性的关系。 结果表明: PAR和PMR树脂的固化机理不同, PAR主要通过炔基间的加成和Diels-Alder反应实现分子间的固化交联, 并最终形成由苯环和稠芳环组成的芳构网络; PMR则主要通过硅氢基、 炔基、 烯基之间的加成反应实现固化, 并成形饱和的碳硅Si—C(sp3)网络结构。 固化成型的芳构网络和Si—C(sp3)网络结构分别赋予了PAR和PMR树脂固化物良好的热稳定性能, 它们的热分解温度Td5均大于600 ℃, 900 ℃残重率均达到85%以上。

In the present report, the curing behavior of two thermoset resins containing silicon alkynyl group- PAR and PMR, and the correlation between the curing structure of resin and their thermal stability were investigated by FTIR, 13C NMR, DSC and TGA techniques. The IR and NMR results showed that the curing mechanism of PAR and PMR resin is different. Based on aromatic cyclization among alkynyl groups and Diels-Alder reaction, aromatic frame network structure constituted by benzene cycles and condensed aromatic cycles are formed in the PAR cured resin. Using additional reaction among Si—H group, alkynyl group and alkenyl group, saturated Si—C(sp3) network structure is formed in the PMR cured resin. The aromatic frame network structure and Si—C(sp3) network structure provide good thermal stability for PAR and PMR resin respectively. The thermal decomposition temperatures Td5 of both resins are above 600 ℃, and the residues percentages at 900 ℃ are above 85%.