新型含氟聚酰胺酰亚胺的合成与性能

Synthesis and properties of novel fluorinated poly(amide-imide)s

由于芳香族聚酰胺酰亚胺(PAI)的溶解性较低,限制了其在溶液加工方法中的应用。为了提高PAI的溶液加工性、降低溶剂使用成本并提高热性能,研究了三苯环结构和氟取代对PAI的性能影响,以苯甲醛和对三氟甲基苯甲醛与2,6-二甲基苯胺为原料,合成了新的二胺化合物4-[(4-氨基-3,5-二甲基苯基)苯基甲基]-2,6-二甲基苯胺(ADPD)、4-[(4-氨基-3,5-二甲基苯基)[4-(三氟甲基)苯基]甲基]-2,6-二甲基苯胺(ADFPD),再与偏苯三酸酐酰氯合成了含新结构的PAI。通过傅里叶变换红外光谱、核磁共振氢谱等对单体和聚合物进行表征,通过分析证明成功合成新型PAI;采用差示扫描量热分析、热重分析、水接触角、溶解性能测试对PAI性能进行了表征。结果表明,制备的聚合物均具有良好的热稳定性能和溶解性,玻璃化转变温度大于300℃,在氮气的环境下5%热失重温度在430℃及以上,最大热失重温度在600℃以上;在类似化学结构上,对比未引入—CF_(3)的PAI-1和引入—CF_(3)的PAI-2的测试结果,发现PAI-2在溶解性和热性能上均优于PAI-1,并且能够明显降低聚合物的表面能,表明—CF_(3)能够有效提高PAI的部分性能。

Due to the low solubility of aromatic polyamide imide(PAI),its application in solution processing methods is limited.In order to improve the solution processability of PAI,reduce the cost of solvent usage and improve its thermal properties,the effects of the triphenyl ring structure and fluorine substitution on the properties of PAI were investigated.and new diamine compounds 4-[(4-amino-3,5-dimethylphenyl)]-2,6-dimethylaniline(ADPD)and 4-[(4-amino-3,5-dimethylphenyl)[4-(trifluoromethyl)phenyl]methyl]-2,6-dimethylaniline(ADFPD)were synthesized by using benzaldehyde and p-trifluoromethyl benzaldehyde with 2,6-dimethylaniline as the raw materials.Then with trimellitic anhydride chloride to synthesize PAI containing the new structure.The monomers and polymers were characterized by fourier transform infrared spectroscopy,nuclear magnetic resonance hydrogen spectroscopy and other characterization methods,which proved the successful synthesis of the new PAI.The properties of PAI were characterized by differential scanning calorimetry,thermogravimetry analysis,water contact angle,and solvency property test.The results show that these polymers all possess good thermal stability properties as well as good solubility,with glass transition temperatures greater than 300℃,5%heat loss temperatures at 430℃and above in nitrogen environment.Maximum heat loss temperatures above 600℃under nitrogen.On the basis of the similar chemical structure,comparing the test results of PAI-1 without—CF_(3)and PAI-2 introduced—CF_(3),it is found that PAI-2 is better than PAI-1 in solubility and thermal properties,and it can significantly reduce the surface energy of the polymer,which indicates that—CF_(3)group can effectively improve some of the properties of PAI.