聚醚聚氨酯-聚醚聚酰亚胺合金相结构的研究

通过不同分子量的对－氨基苯甲酸酯封端的聚（四次亚甲基）醚和均苯甲甲酸二酐反应，合成了聚醚聚酰胺酸；然后以不同重量比将聚醚聚氨酯和聚醚聚酰胺酸溶液混合反应亚胺化，制备了一系列不同硬段含量的聚醚聚氨酯－聚醚聚酰亚胺合金。用傅立叶变换红外光谱、动态力学分析、示差扫描量热、广角Ｘ－衍射、应力应变试验等分析测试方法对合金进行了研究，结果表明聚醚聚氨酯－聚醚聚酰亚胺合金具有很好的相分离结构，是一类新型耐高温、有韧性的热塑性弹性体。聚醚分子量相同的聚氨酯和聚酰亚胺形成的合金软段相容，合金具有两相结构；聚醚分子量不同的聚氨酯和聚酰亚胺形成的合金软段存在相分离，合金具有三相结构，表现在材料外观上分别为透明不透明的韧性膜，少量聚酰亚胺的掺入，能大大增加材料的耐热性能，而合金的材料力学性能没有明显变化。

Phase Structure Studies of Polyether-polyimide/Polyether-polyurethan blends

A novel type of polyurethane (PU) and polyether polyimide (PI) blends were prepared in two steps. The first step was the preparation of polyether amic acid by the reaction of oligmers with benzenetetracarboxylic acid dianhydride (PMDA). The oligmers are polytetramethylene oxide glycol di p aminobenzoate (APTMO) with molecular weight 1 000 and 2 000. The second step was mixing the THF solutions of polyether polyurethane and polyether polyamic acid in various weight ratios. The blend films were obtained by casting and then heating imidization. Infrared spectroscopy, dynamic mechanical analysis, differential scanning calorimetry and strain stress testing were used to study this family of blends. The results showd that the thermal stability of PU is improved obviously by the incorporation of PI. The tensile properties of the blends are not changed significantly compared with PU 1000. The blends are a novel type of thermoplastic elastomers, which exhibit a well phase-separated morphology and possess a wide range of service temperature.