含苯并咪唑基团CPI薄膜的制备及性能

Preparation and Properties of CPI Film Containing Benzimidazole Group

采用5-氨基-2-(4-氨基苯基)-苯并咪唑(DAPBI)为改性单体,与4,4′-(六氟异丙烯)二酞酸酐(6FDA)、2,2′-二(三氟甲基)二氨基联苯(TFMB)共聚合成了一系列聚酰胺酸(PAA)溶液。经流延涂膜、去溶剂和亚胺化等步骤制备了一系列无色透明聚酰亚胺(CPI)薄膜。利用紫外-可见分光光度计、差示扫描量热仪、电子万能试验机等对预聚体和CPI薄膜的结构与性能进行了研究。结果表明:DAPBI的引入使得CPI薄膜的透光性略有降低,但可有效提高其耐热性能和力学性能。其中二胺中TFMB与DAPBI物质的量之比为6.00∶4.00时,CPI薄膜在500 nm处的透光率为88.04%,玻璃化转变温度为340.54℃,拉伸强度为86.0 MPa。

A series of polyamic acid(PAA)solutions were synthesized by copolymerization of 4,4′-hexafluoroisopropyl phthalic anhydride(6FDA),2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl(TFMB)and using 2-(4-aminophenyl)-5-aminobenzimidazole(DAPBI)as the modified monomer.The colorless transparent polyimide(CPI)films were prepared by tape casting,solvent removal and imidization.The structure and properties of precursors and CPI films were studied by UV-visible spectroscopy,differential scanning calorimetry and electronic universal testing machine.The results show that the introduction of DAPBI reduces the light transmittance of CPI slightly,but can effectively improve its heat resistance and mechanical properties.When molar ratio of TFMB to DAPBI in diamine is 6.00∶4.00,the light transmittance of CPI film at 500 nm is 88.04%,the glass transition temperature is 340.54℃,and the tensile strength is 86.0 MPa.