纳米Al_2O_3的晶型对聚酰亚胺杂化薄膜性能的影响

Effect of nano Al_2O_3 crystallographic structure on properties of polyimide hybrid films

将经偶联剂处理的纳米Al2O3粉体,借助超声波以一定方式均匀分散于聚酰胺酸溶液中,制备出Al2O3不同晶型、不同含量的PI/纳米Al2O3杂化薄膜,并对杂化薄膜微观形貌、聚集态结构、光透过率、热稳定性、电击穿场强进行研究,分析Al2O3晶型和含量对PI/纳米Al2O3杂化薄膜的结构和性能的影响.结果表明:PI/纳米Al2O3杂化薄膜的热稳定性,电击穿场强均高于纯PI薄膜,且随着纳米Al2O3含量的提高热稳定性也随之提高,电击穿场强先升高后降低;填充Al2O3粉体的晶型对PI薄膜分子链堆积密度有较大的影响,导致添加不同晶型Al2O3的杂化薄膜性能的差异.

To prepare PI/nano Al2O3 hybrid films with different Al2O3 contents and crystallographic structures, the nano Al2O3 treated by coupling agent was dispersed uniformly in polyamic acid by ultrasonic wave. The micro morphology, aggregation structure and performances such as optical throughput, thermal stability and electric breakdown strength were studied. The effects of crystal structure and contents of nano-Al2O3 on the microstructure and properties of PI/nano Al2O3 hybrid films were also investigated. Results show that the thermal stability and electric breakdown strength of PI/nano Al2O3 hybrid films are higher than those of pure PI film; the thermal stability is enhanced with the increasing of Al2O3, and the electric breakdown strength is intensified firstly and weakened then. The crystallographic structure of Al2O3 powder has major influence on PI molecular chain＇ s bulk density, which results in the property variance of hybrid films.