高分子量聚对苯撑苯并双口恶唑的合成及性能研究

Study on synthesis of poly-p-phenylene benzobisthoxazole with high molecular weight(HMW PBO)and its performance

采用4,6-二氨基-1,3苯二酚磷酸盐(DAR.2H3PO4)和对苯二甲酸(TPA)为原料,在氮气保护下,多聚磷酸介质中经缩聚得到聚对苯撑苯并双口恶唑(PBO)。通过重结晶使4,6-二氨基-1,3苯二酚磷酸盐纯度达到99.8%。考查了不同五氧化二磷含量和最高反应温度对聚合的影响,通过实验得到的最佳工艺条件是:聚合温度为120～180℃,控制最终五氧化二磷的质量分数ω(P2O5)=83.5%～84.5%。采用红外光谱、元素分析、XRD对PBO结构进行表征,热重分析表明PBO在氮气和空气中有很好的稳定性,在甲烷磺酸(30±0.1)℃中测得PBO特性黏度为20.4dL/g。

Poly-p-phenylene benzobisthoxazole（PBO）was synthesized in polyphosphoric acid by polycondensation of 4,6-diamino-1,3-benzenediol diphosphate and terephthalic acid under the atmosphere of nitrogen.More than 99.8% in purity of 4,6-diamino-1,3-benzenediol diphosphate can be achieved by recrystallization.The effects of reaction temperature and final concentration of P2O5 were investigated.The optimized technological conditions were as follows：controlling the reaction temperature at 120~180℃,ω（P2O5）=83.5~84.5%.Performance and properties of the polymer obtained were characterized by FTIR,elementary analysis and XRD.Analyzed by thermogravimetric analysis（TGA）,obtained PBO showed great stability both in nitrogen and air.The intrinsic viscosity of PBO was 20.4dL/g tested in methanesulfonic acid at（30±0.1）℃.