纳米Al_2O_3/PI三层复合薄膜的制备与表征

Preparation and characterization of nano-Al_2O_3/PI trilayer composite films

以3,3′,4,4′-二苯酮四甲酸二酐(BTDA)和4,4′-二氨基二苯醚(ODA)为缩聚单体,利用高压静电纺丝技术制备出纳米Al_2O_3/PAA(聚酰胺酸)复合薄膜.以均苯四甲酸二酐(PMDA)和4,4′-二氨基二苯醚(ODA)为原料制备出聚酰胺酸铺膜胶液,在电纺膜的两侧进行流延成膜,并热亚胺化处理.对复合薄膜进行化学组成、微观形貌、耐电晕性能、力学性能和热学性能测试分析.结果表明:复合薄膜的亚胺化较完全,纳米Al_2O_3均匀地分散在聚酰亚胺基体中,在纳米氧化铝掺杂量为6%时综合性能最佳,耐电晕老化时间为12.3 h,是未掺杂纳米氧化铝三层复合薄膜的3倍以上,拉伸强度达到最大值(174 MPa),同时断裂伸长率达到21%.纳米Al_2O_3的加入使得复合薄膜的热稳定性有所提高,起始热分解温度从578.7℃提高到591.3℃.

3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA) and 4,4′-diaminodiphenyl ether (ODA) were used as condensation monomers to prepare nano-Al 2O 3/PAA (polyamic acid) composite film by high-voltage electrospinning technology. Polyamic acid solution was prepared with pyromellitic dianhydride (PMDA) and 4,4′-diaminodiphenyl ether (ODA) as raw materials, and the film was cast and heated on both sides of the electrospun film. The chemical composition, microscopic morphology, corona resistance, mechanical properties and thermal properties of the composite film were tested and analyzed. The results show that the imidization of composite film is complete, and the nano-Al 2O 3 is uniformly dispersed in the polyimide matrix. When the nano-Al 2O 3 doping amount is 6% with the best overall performance, the corona aging time is 12.3 h, which is 3 times than that of undoped. The maximum tensile strength of the three-layer composite film is 174 MPa, while the elongation at break is also high up to 21%. The addition of nano-Al 2O 3 can improve the thermal stability of composite film, and the initial thermal decomposition temperature is increased from 578.7 ℃ to 591.3 ℃.