轨道交通设备用聚酰亚胺/氧化铝纳微米复合材料的制备及性能研究

Preparation and Characterization of Polyimide/Alumina Nano-micro Composites for Rail Transportation Equipment

聚酰亚胺薄膜作为高速列车变频牵引电机重要的绝缘材料被广泛应用于电机绝缘系统。采用一定比例的微米级、亚微米级、纳米级3种粒径的氧化铝级配混合获得了复合填料,并通过原位聚合法制备了面向轨道交通的绝缘聚酰亚胺/氧化铝纳微米复合材料,研究了不同氧化铝颗粒粒径级配和亚胺化终止温度对复合材料性能的影响。结果表明,氧化铝3种颗粒粒径30 nm/0.2μm/1μm的级配比为1:2:7时,采用合适的亚胺化终止温度制备的聚酰亚胺复合薄膜具有优良的导热性能,同时还具有良好的力学性能、电气性能与热稳定性等综合性能。

Polyimide(PI) is widely used as an important insulating material for the inverter-fed traction motors of the highspeed trains. The mixed alumina fillers were prepared by using macro, sub-micro and nano alumina particles. The polyimide/alumina composites were prepared by in-situ polymerization. The effect of the ratio of particle size(30 nm/0.2 μm/1 μm) and the imidization temperature on the properties of the polyimide composites was investigated. The results show that the polyimide composite films prepared at the appropriate imidization temperature have good thermal conductivity, mechanical properties, electrical properties and thermal stability when the ratio of alumina particle size(30 nm/0.2 μm/1 μm) is 1:2:7.