用红外光谱方法分析了聚对苯甲酰胺(Ⅰ)和聚对苯二甲酰对苯二胺(Ⅱ)的谱带特征及其与结构的关系,指出了两者的区别,并用二向色性观察了薄膜的取向态,改进了化学分析方法,从(Ⅱ)的水解产物中分离和鉴定了对苯二甲酸和对苯二胺,确定了Kevlar-49纤维的结构属于(Ⅱ),还用差热分析方法比较了T_m和T_d等数据。 The spectral characteristics of poly (p-benzamide) (Ⅰ) and poly (p-phenyleneterephthalamide) (Ⅱ) and their relationship with structure were analyzed by infrared spectroscopy. The differences between the two were pointed out. The orientation state of the film was observed, the chemical analysis method was improved, terephthalic acid and p-phenylenediamine were separated and identified from the hydrolyzate of (Ⅱ), the structure of Kevlar-49 fiber was found to belong to (Ⅱ) The data of T_m and T_d were compared by differential thermal analysis.