BPDA/PDA系列聚酰亚胺的共聚改性研究

Modification and Characterization of BPDA/PDA Copolyimide

以联苯四甲酸二酐(BPDA)、二苯醚四羧酸二酐(ODPA)和对苯二胺(PDA)为单体,通过低温共聚反应合成了系列超高分子量的BPDA-ODPA共聚酰胺酸,其特性粘度均在6.0 dL/g左右.动态机械性能测试表明由此系列高分子量共聚酰胺酸亚胺化形成的共聚酰亚胺薄膜的Tg由330℃(BP-PI)降至273.9℃(PI-6/4).实验结果还表明PI-6/4的拉伸强度高达523 MPa,与BP-PI工业化产品相当,且溶解性得到改善.

A series of high molecular weight PI precursors, poly （p-phenylene biphenyhetracarboxamic-cooxydiphthaldicarboxamic acid） were synthesized from 3,4,3＇ ,4＇-biphenyltetracarboxylic dianhydride （BPDA）, 4,4＇-oxydiphthalic anhydride（ODPA） and p-phenylenediamine（PDA） by using intense mechanical stirring at - 15 ℃ to 10 ℃. The intrinsic viscosity of these as-synthesized PI precursors was around 6.0 dL/g. When the ratio of BPDA and ODPA was 6/4, the glass transition temperature of the co-PI fell from 330 ℃ of BP-PI to 273.9 ℃ of the co-PI, and the tensile strength was 523 MPa, which was similar to that of the commercially available BPDA/PDA PI thin film.