高热稳定性的含联苯醚腈链段的双邻苯二甲腈性能研究

Study on the properties of high temperature resistant phthalonitrile oligomer containing biphenyl ethernitrile

以芳香二元胺2,6-二-4-氨基苯氧基苯甲腈(BDB)为固化交联剂,采用溶液聚合的方法制备了不同预聚程度的含联苯醚腈链段的双邻苯二甲腈(2PEN-BPh)聚合物,并研究了预聚程度对其性能的影响。通过DSC和流变研究了2PEN-BPh聚合物在交联剂作用下的固化反应行为,使用TGA跟踪了聚合物不同反应阶段的热性能。结果表明,2PEN-BPh具有可交联反应活性,其交联过程可以通过控制固化交联剂BDB的含量来控制;当交联剂含量为3%(质量分数)时,2PEN-BPh的最佳预聚时间为2h。TGA结果显示2PEN-BPh聚合物具有优异的热稳定性和热氧稳定性,完全固化的2PEN-BPh在氮气和空气中的起始分解温度均在515℃以上,分解5%的温度超过556℃,800℃时的残炭率在氮气中达78%以上,而在空气中也仍有44%以上。

In this paper, some phthalonitrile prepolymers containing biphenyl ethernitrile with different prepolymerization extent were synthesized. During this procedure, 2, 6-bis（4-diaminobenzoxy） benzonitrile（BDB） was used as curing agent and the effect of different reaction extent on the properties of 2PEN-BPh oligomer. The curing reaction behaviors of the oligomer and prepolymers were studied by DSC and rheological analysis. TGA was used to conduct the thermal stability of the cured 2PEN-BPh polymers. The results showed that prepolymerization for 2h was the optimal prepolymerization time when the concentration of curing agent was 3% by weight;and the 2PEN-BPh polymers processed good thermal and thermo-oxidative stabilities, fully cured 2PEN-BPh exhibited the initial decomposing temperature above 515℃, and the temperatures at weight loss 5% was exceeded 556℃, the char yields at 800℃ were above 78% in nitrogen and above 44% in air.