【摘要】 采用4,6-二氨基间苯二酚盐酸盐和对苯二甲酸制备的络合盐,在多聚磷酸体系中缩聚制备聚对苯撑苯并双噁唑(PBO),反应在聚合反应釜与双螺杆挤出机中完成。采用黏度测试、红外光谱(FT-IR)、热失重(TG-DTG)和紫外可见光谱(UV)等分析方法,对反应不同阶段的聚合物黏度、分子量、结构进行了表征,对分子量的增长过程进行研究。实验结果表明,采用络合盐聚合能够制备出高分子量聚合物,后期采用双螺杆挤出机进行聚合,进一步提高了聚合物的均匀性和分子量。液晶相聚合时,主要是扩散控制。更多还原

【Abstract】 4,6-diamino-1,3-benzenediol/terephthalate(TA salt) was prepared from 4,6-diamino-1,3-benzenediol and terephthalic acid.Poly(p-phenylenebenzobisoxazole)(PBO) was prepared from TA salt in polyphosphoric acid by a solution polycondensation.Polymerization reaction achieved in a kettle reactor and in the Twin-screw extruder.The obtained produces at each reaction steps was characterized by FT-IR,UV,TG-DTG,and its inherent viscosity is 21.58 dL/g.This method of polymerization can shorten the reaction time and obtain PBO with high molecular weight.The growth process of the molecular weight has been studied and the polymerization mechanism has been discussed.The experimental results indicate that high molecular weight polymer can be prepared by using the method of the complex salt.The polymerization proceeds in the twin-screw extruder to increase the uniformity and the molecular weight of polymer in the late reaction.Liquid crystal phase polymerization is controlled by the pervasion.更多还原