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 diamines

对苯二酚依次与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,还原后制备了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、力学性能进行了测试。结果表明,基于4,4'-氧双邻苯二甲酸酐和六氟二酐的PI在常见有机溶剂中均具有良好的溶解性。N2氛围下,这些PI的5%和10%热失重温度分别在548.8~594.2和566.3~609.7℃之间,玻璃化转变温度在226~290℃之间,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范围内,500 nm处的透过率在52%~78%范围内,拉伸强度为98.3~110.5 MPa,杨氏模量为1.86~2.14 GPa,断裂伸长率为9%~23%。

Four aromatic polyimides(PI)were synthesized from a two-step polymerization of several dianhydrides with a fluorinated diamine monomer containing pyridine,6-{4-[4-amino-2-(trifluoromethyl)phenoxy]phenoxy}pyridin-3-amine,which was prepared from nucleophilic substitution reaction of hydroquinone with 2-chloro-5-nitrobenzotrifluoride and 2-chloro-5-nitropyridine successively and reduction reaction.The solubility,thermal stability,mechanical properties,and optical properties of the PI samples obtained were then investigated.The results showed that the PI samples based on 4,4'-oxydiphthalic anhydride and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride exhibited outstanding solubility in commonly used organic solvents.Under N2 atmosphere,the 5%and 10%mass loss temperatures were 548.8~594.2 and 566.3~609.7℃,respectively,and the glass transition temperatures were in the range from 226 to 290℃,indicating the excellent thermal stability of the PI samples.These PI films also displayed good optical transparency and mechanical properties with cut-off wavelengths of 382~438 nm,transmittance at 500 nm of 52%~78%,tensile strength of 98.3~110.5 MPa,Young's modulus of 1.86~2.14 GPa,and elongation at break of 9%~23%.