含叔丁基、醚键和双酚A单元可溶性聚酰亚胺的合成与表征

Synthesis and Characterization of Soluble Polyimides Containing tert-Butyl,Ether Linkages and Bisphenol A Units

通过分子设计合成了一种含叔丁基、醚键和双酚A单元的二胺单体2，2-二（3’-叔丁基4’-氨基二苯醚-4-基）丙烷（4），然后将其与4种商品化的芳香二酐单体：联苯四羧酸二酐（BPDA）、二苯醚四酸二酐（OPDA）、二苯六氟异丙基四酸二酐（6FDA）和均苯四酸二酐（PMDA）经高温“一步法”制备了一系列新型聚酰亚胺（PI）树脂，并对它们的结构与性能进行了研究．结果表明，该系列PI在NMP、DMF、DMAc、THF和CHCI，等普通有机溶剂中具有良好的溶解性；玻璃化转变温度Tg（DSC）在265-302℃之间，5％热失重温度（N2氛围）在519℃以上；在400～760nm可见光波长范围内，具有优异的光学透明性，透光率约等于或大于90％；PI的数均分子量（Mn,GPC）在1．90×10^4～3．90×10^4范围内，分子量分布（PDI）介于2．63～4．63之间，x-射线衍射（XRD）结果表明所得PI为无定形聚合物，吸水率低于0．5％．叔丁基、醚键和双酚A单元同时引入具有协同效应，可提高PI的溶解性和透明性，并保持PI原有良好的热稳定性、机械性能和较低的吸水率．

A novel diamine monomer containing tert-butyl, ether linkages and bisphenol A unit,2,2-bis （3＇- （tert-butyl）-,4＇-aniline-bisphenyl-4-ehter） propane （4）, was designed and synthesized from 2-tert-hutylaniline and bisphenol A. Then it was polymerized with several commercial aromatic dianhydrides, including OPDA, PMDA,6FDA and BPDA,via one-pot method to afford a series of aromatic polyimides. Their chemical structures are confirmed by NMR,FTIR and EA measurements. The number-averaged molecular weights of the resulting PIs are in the range from 1.9× 10^4 to 3.9 × 10^4 with PDI from 2. 63 to 4. 63 by GPC measurements. They exhibit excellent solubility in many organic solvents, such as NMP, DMF, m-cresol, DMAc, THF and CHC13 ere, which can be attributed to the incorporation of tert-butyl groups and bisphenol A units into their rigid backbones. They can form transparent films by solution casting and the light transparency was equal to or higher than 90% in the visible light range from 400 to 760 nm. The XRD results demonstrate that they are amorphous glassy polymers. Furthermore, their inherent outstanding performance is still retained, including the high 5% weight loss temperature in nitrogen and Tg,good mechanical properties and low water absorption rates.