中文摘要：

为研究不同柔顺性链段对聚噁二唑结构与性能的影响,以多聚磷酸（PPA）为溶剂和脱水剂,脂肪族二羧酸和硫酸肼为单体,一步法制备了一系列分子主链中含有亚甲基柔性链段（—（CH2）n—,n=4、6、8）的脂肪族聚噁二唑,并通过傅里叶红外（FT-IR）、特性黏数（[η]）、热失重（TG）、差示扫描量热法（DSC）等表征方法对聚合物的结构与性能进行了初步研究。结果表明：二酸单体中亚甲基个数的增加,有利于避免聚合过程中分子链端发生副反应形成酰肼环结构,从而得到分子量较高的聚合物;与芳香族聚噁二唑相比,脂肪族聚噁二唑柔性链段烷基的引入,利于分子链排列形成有序结构,从而具有良好的结晶性,熔点在130℃左右,同时热稳定性降低。

英文摘要：

In order to study the influnce of chain segment with different flexibilities on the structure and performance of polyoxadiazole,aliphatic polyoxadiazole incorporating a methylenic sequence（with number of-（CH2）n-,units n = 4,6,8） in the main chain were obtained by a novel one-step polycondensation of aliphatic dicarboxylic acids with hydrazine sulfate using polyphosphoric acid（PPA） as both solvent and dehydrolyzing agent.The preliminary study on the structure and properties was conducted by Fourier Transform Infrared（FT-IR）,Intrinsic viscosity（[η]）,Thermogravimetry（TG）,Differential Scanning Calorimetry（DSC） and so on.As the number of methylenes in acid monomer increasing,which is beneficial to avoid the formation of hydrazide ring at the end of molecular chain through the side reaction in polymerization process,high molecular weight polymer can be obtained.The heat resistance of aliphatic polyoxadiazole decreases obviously comparing with aromatic poly（1,3,4-oxadiazole） and the aliphatic polyoxadiazoles lower the melting point（around 130℃） and highten the crystallinity because the introduction of flexible alkyl chain conduces to the formation of ordered structure.