基于苯醚型含氟二胺的聚酰亚胺膜材料的合成与表征

4,4′-二羟基二苯醚和2-氯-5-硝基三氟甲苯经Williamson反应得到4,4′-双(4-硝基-2-三氟甲基苯氧基)二苯醚;在Pd/C-水合肼还原作用下得到4,4′-双(4-氨基-2-三氟甲基苯氧基)二苯醚(p-6FAPE).采用3种苯醚型含氟二胺1,4-双(3-氨基-5-三氟甲基苯氧基)苯、1,4-双(4-氨基-2-三氟甲基苯氧基)苯和p-6FAPE分别与3,3′,4,4′-二苯醚四酸二酐(ODPA)和均苯四甲酸二酐通过两步法制备出6种含氟聚酰亚胺(PI),对其溶解性、热性能和光学性能进行研究.这些PI具有较好的溶解性,且具有良好的热稳定性;ODPA基PI在可见光波长范围具有优良的透明性,450 nm处的透光率超过80%.

SYNTHESIS AND CHARACTERIZATION OF POLYIMIDES BASED ON PHENYL ETHER TYPE TRIFLUROMETHYL-CONTAINING DIAMINES

4, 4'-Bis (4-nitro-2-trifluoromethylphenoxy) diphenylether (p-6FNPE) was synthesized by the Williamson reaction between 4, 4'-dihydroxydiphenyl ether and 2-chlorine-5-nitro-trifluoromethyl benzene. Then,the reduction systems of Pd/C-hydrazine hydrate were adopted to obtain the corresponding products 4, 4'-bis(4-amino-2-trifluoromethylphenoxy) diphenylether (p-6FAPE). Using three kinds of phenyl ether type trifluoromethyl-containing diamine,i. e. , 1 ,4-bis(3-amino-5-trifluoromethylphenoxy)benzene (m-6FAPB) ,1, 4-bis(4-amino-2-trifluoromethyl phenoxy)benzene (p-6FAPB) and p-6FAPE,and two kinds of dianhydride, i. e. , 3, 3', 4, 4'-oxydiphthalic anhydride ( ODPA ) and pyromellitic dianhydride ( PMDA ) , six kinds of fluorine-containing polyimide (PI) films were prepared by the two-step method. The chemical structure and properties of the PI were characterized by FTIR, UV-Vis and TGA. The six kinds of fluorine-containing PI showed good solubility in aprotic polar organic solvents such as NMP,DMF and DMAc. PI obtained from m- position diamine showed better solubility. All the fluorine-containing PI films had good thermal stability, with a 5% weight loss temperature at 540℃ or higher. In the case of a same dianhydride, PI based on 6FAPE possessed higher thermal resistance than 6FAPB. Compared with PI based on PMDA, fluorine-containing PI films based on ODPA exhibited more excellent transparency in the visible wavelength range (400 ～700 nm) , and their transmittance at 450 nm was over 80% . PI based on p-6FAPB exhibited better transparency than p-6FAPE. PI films obtained from m-6FAPB tended to be colorless and transparent. The PI synthesized in this work could be expected to be used in the applications such as solar cell substrate and waveguide board materials.