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采用低温溶液缩聚法,在N-甲基吡咯烷酮(NMP)-氯化锂(LiCl)溶剂体系中加入2-(4-氨基苯基)-5-氨基苯并咪唑(DAPBI)作为第三单体,与对苯二胺(PPD)和对苯二甲酰氯(TPC)共聚得到改性对苯二甲酰对苯二胺(PPTA)共聚物.控制共聚单体投料顺序,设计合成出一系列序列结构不同的杂环段与PP-.TA硬段相间的嵌段聚合物.研究了序列结构和DAPBI含量对共聚物比浓对数黏度的影响,采用红外光谱、X射线衍射、热重分析仪等对共聚物结构和性能进行表征.试验结果表明:DAPBI成功引入到了PPTA分子链中,改性PPTA树脂为非晶结构,所得有规嵌段共聚物比无规共聚物拥有更好的有序性和结晶性能,共聚物能保持良好的耐热性能,溶解性能和力学性能得到了提升.“,”Modified PPTA copolymer was obtained by low temperature solution polymerization using phenylenediamine(PPD),paraphthaloyl chloride(TPC) and the third monomer 2-(4-Aminophenyl)-1H-benzimidazol-5-amine(DAPBI) in the solvent system N-methyl pyrrolidone/lithium chloride(NMP/LiC1).A series of different sequences structure of alternating block copolymers containing heterocyclic blocks and hard blocks of poly(p-phenylene terephthalamide) (PPTA) were designed and synthesized.The influences of sequence structure and DAPBI content on inherent viscosity of the PPTA block copolymer were investigated systematically.The structure and properties of copolymer were characterized by FTIR,XRD,TG.The results indicated that the DAPBI monomer was successfully introduced to the PPTA chain and the modified PPTA was amorphous structure.The block copolymers had better order and crystallinity than the random copolymers.The heat resistance remained fairly good.The solubility in common organic solvents and mechanical properties had been improved.