不同比例的s-BPDA/i-BPDA型聚酰亚胺共聚结构与性能关系

由不同比例的二酐单体3,3′,4,4′-联苯四酸二酐(s-BPDA)/2,2′,3,3′-联苯四酸二酐(i-BPDA)与二胺单体4,4′-二氨基二苯醚(4,4′-ODA)制得了一系列共聚可溶聚酰亚胺. 采用DSC 、TGA和拉伸等测试方法对所得共聚聚酰亚胺进行了表征, 实验结果表明, 所得聚酰亚胺具有优异的力学性能和热稳定性, 并且随着i-BPDA含量的增加, 聚酰亚胺的溶解性提高, 玻璃化转变温度(Tg)升高, 中间体聚酰胺酸的固有黏度降低.

Synthesis and Characterization of Copolyimides from s-BPDA/i-BPDA with Different Molar Ratio

A series of organosoluble copolyimides was successfully synthesized from the 2,2′,3,3′-biphenyltetracarboxylic dianhydride(i-BPDA) and 3,3′,4,4′-biphenyltetracarboxylic dianhydride(s-BPDA) with aromatic diamine 4,4′-ODA.The copolyimides were characterized by FTIR, DSC, TGA and DMA. The copo-lyimides hold superior mechanical properties and show improved solubilities, depending on the i-BPDA content. A regular increase of glass transition temperatures and a decrease of inherent viscosities of copolymers with increasing content of i-BPDA were also observed.