基于一种含吡啶的氟化二胺的聚酰亚胺合成与性能

Synthesis and properties of polyimides based on pyridine-containing fluorinated diamine

摘要:

以对苯二酚为原料，依次与2-氯-5-硝基三氟甲苯和2-氯-5-硝基吡啶进行亲核取代反应，还原后制备得到一种含吡啶杂环的氟化二胺单体6-{4-[4-氨基-2-(三氟甲基)苯氧基]苯氧基}吡啶-3-胺，并采用两步法将其与二酐聚合，得到4种芳香族聚酰亚胺（PI）。对所得PI的溶解性、耐热稳定性、光学性能、力学性能等进行表征。结果表明，基于4,4'-氧双邻苯二甲酸酐（ODPA）和六氟二酐(6FDA)的PI在常见有机溶剂中都有不错的溶解性。N2氛围下，这些PI的5 %、10 %热失重温度分别在548 ℃和566 ℃以上，玻璃化转变温度在226~290 ℃，具有良好的耐热稳定性。这些PI薄膜有较好的光学透明度和力学性能，截止波长在382~438 nm，500 nm处的透过率在62 %~78 %，拉伸强度为98.3~110.5 MPa，弹性模量为1.86~2.14 GPa，断裂伸长率为9~23 %。

Abstract:

A fluorinated diamine monomer containing pyridine, 6-(4-(4-amino-2-(trifluoromethyl) phenoxy) phenoxy) pyridin-3-amine, was prepared by nucleophilic substitution reaction with 2-chloro-5-nitrobenzotrifluoride and 2-chloro-5-nitropyridine in turn using hydroquinone as raw material and reduction. Four new polyimides (PI) were produced by the conventional two-step method with several dianhydrides. The solubility, thermal stability, mechanical properties, and optical properties of the resulting PIs were characterized. The results showed that the PIs based on 4,4’-oxydiphthalic anhydride (ODPA) and hexafluorodianhydride (6FDA) have outstanding solubility in common organic solvents. In N2 atmosphere, the temperatures of these polyimides with 5% and 10% weight loss are above 548 ℃ and 566 ℃, and the glass transition temperatures are between 226 and 290 ℃, which have excellent thermal stability. These PI films have good optical transparency and mechanical properties with cut-off wavelengths of 382~438 nm, transmittance at 500 nm of 62%~78%, tensile strength of 98.3~110.5 MPa, tensile modulus of 1.86~2.14 GPa, and elongation at break of 9~23 %.