苯乙炔苯酐型热固性聚酰亚胺的合成与表征

Synthesis and Characaterization of Polyimide Terminated with Phenylethynylphthalic Anhydride

以4-溴代苯酐为原料,二(三苯基膦)二氯化钯为催化剂,三苯基膦为配体,三乙胺为反应副产物吸收剂,在非质子性溶剂N,N-二甲基乙酰胺中与苯乙炔进行交叉偶联反应,制得4-苯乙炔苯酐,然后以其为封端剂制备了聚酰亚胺;对苯乙炔苯酐及其封端的聚酰亚胺进行了结构及性能的表征。结果表明,用苯乙炔苯酐封端的聚酰亚胺,交联后薄膜的最高拉伸强度和最大断裂伸长率分别为112.9MPa和20.7%,聚酰亚胺薄膜的玻璃化转变温度和5%的热分解温度分别为313.1℃和550.0℃。

4-phenylethynylphthalic anhydride （4-PEPA） was synthesized via the palladium catalyzed crosscoupling reaction of 4-bromophthalic anhydride and phenylacetylene in the presence of his （triphenylphosphine） palladium dichloride as catalyst, triphenylphosphine as ligand, triethylamine as absorbent and dimethylacetamide as the solvents. The prepared 4-phenylethynylphthalic anhydride was then used end capping agent to prepare polyimide. The structure and properties of 4-PEPA and the PI end-capped with 4-PEPA were characterized by means of FT-IR, elemental analysis, DSC and thermogravimetric analysis. The results indicated the maximum tensile strength and elongation at break of the cured film of the PI end-capped with 4-PEPA were 112.9MPa and 20.7% respectively after curing. The glass transition temperature and the temperature of 5 wt% thermal weight loss were 313.1 ℃ and 550.0 ℃ respectively.