高残炭硼酚醛树脂的制备

Phenolic resin (PF) is widely used because of its good heat resistance and mechanical properties. However, its heat resistance can no longer meet the requirements of modern aerospace technology. Research has found that by modifying phenolic resin with boric acid, boron phenolic resin (BPF) with excellent high-temperature resistance can be prepared. When boron phenolic resin is synthesized by the boric acid ester method, the heat resistance is the best when n(phenol) : n(formaldehyde) = 1 : 1.5. The results of thermal analysis show that the carbon residue rate of the synthesized BPF at 1000 °C is 78%, and its heat resistance is significantly better than that of traditional phenolic resin. At the same time, the influence of different boric acid contents on the heat resistance of BPF is discussed. When n(boric acid) : n(phenol) > 0.33 : 1, the carbon residue rate tends to be stable. In addition, the pre-curing temperature of BPF is determined to be 160 °C and the post-curing temperature is 220 °C by using the differential scanning calorimeter (DSC) method.

酚醛树脂（PF）因其具有良好的耐热性能和机械性能而被广泛应用。但其耐热性能已经满足不了现代航空航天技术的需求，研究发现，采用硼酸对酚醛树脂进行改性，可以制得具有优良耐高温性能的硼酚醛树脂（BPF）。采用硼酸酯法合成硼酚醛树脂，n（苯酚）∶n（甲醛）＝1:1.5 时耐热性最佳。热分析结果表明，合成的bpf在1000℃条件下的残炭率为78％，其耐热性能明显优于传统的酚醛树脂。同时讨论了不同硼酸含量对BPF耐热性能的影响，当n（硼酸）∶n（苯酚）＞0.33∶1时，残炭率趋于稳定。此外，利用差示扫描量热仪（DSC）方法确定BPF预固化温度为160℃，后固化温度为220℃。