硼改性酚醛树脂的结构和耐热性

合成了不同硼含量的改性酚醛树脂(硼酚醛树脂),并分别用红外光谱(FT-IR)、动态力学分析(DMA)和热重分析(TGA)方法对其结构和性能进行了分析。结果表明,165℃时的固化物具有两个玻璃化温度,表明该固化物中同时存在交联和线型两种不同结构的酚醛树脂。固化物的残炭率随硼含量的增加而增加,说明硼的加入使硼酚醛树脂的耐热性得到提高,800℃的残炭率最高可达74.9%,对硼酚醛树脂进行后固化处理可进一步提高其耐热性。

Structure and Heat-Resistance of Boron Modified Phenolic Resin

Boron modified phenolic resins(BPF) with different boron contents were synthesized,and their properties and structure were characterized by Fourier transform infrared spectra(FT-IR),dynamic mechanical analysis(DMA) and thermogravimetric analysis(TGA).The results show that BPF cured at 165 ℃ has two glass transitions,which indicates there are two different macromolecules in the cured BPF,i.e.,crosslinking and linear polymers.The char yield of cured BPF increases with the boron content,the heat resistance of BPF is better than that of phenolic resin without boron,and the maximum of the char yield of BPF0.3 reaches 74.9% at 800 ℃.It is found that the heat resistance of the BPF can be further improved by postcuring.