微胶囊/LLDPE自润滑复合材料的制备及其摩擦性能

Preparation of Self-lubricating Microcapsules and Its Tribological Performance of LLDPE-based Composites

以聚砜为壁材,润滑油为芯材,采用溶剂挥发法制备了润滑油微胶囊,考察了芯壁质量比对微胶囊芯材含量和壁厚的影响。在芯壁质量比为1.25∶1.00,搅拌速度为400 r/min,实验温度为36℃时,所制备的微胶囊具有高的热稳定性,初始降解温度为240℃,平均粒径为130μm,壁厚约5μm,芯材含量为微胶囊质量的53.25%。将制得的微胶囊添加到线性低密度聚乙烯(LLDPE)基体中,制得LLDPE基自润滑复合材料,对其摩擦磨损性能进行了测定,揭示了自润滑机理。结果表明,当润滑油微胶囊添加质量为LLDPE质量的20%时,LLDPE基自润滑复合材料的摩擦系数及磨损率,相较于纯LLDPE分别降低了25.4%和65.3%。

Polysulfone microcapsules containing lubricating oil were successfully prepared using solvent evaporation method. The effect of mass ratio of lubricating oil and polysulfone on the core content and wall thickness of microcapsules were discussed. When the mass ratio of core and wall materials is 1. 25∶1,stirring rate is 400 r/min and the experimental temperature is 36 ℃,the synthesized microcapsules have excellent thermal stability,with a thermal degradation onset temperature of 240 ℃. The mean diameter and wall thickness are approximately 130 μm and 5 μm,respectively. The encapsulation capacity reaches about 53. 25%. Subsequently,the self-lubricating composites were prepared by incorporating microcapsules containing lubricating oil into linear low density polyethylene resin（ LLDPE）,and the tribological properties and the self-lubricating mechanism of the composites were studied. It was found that when the concentration of lubricating oil microcapsules was 20%（ based on mass of LLDPE）,the obtained self-lubricating composite exhibited outstanding tribological performances. The frictional coefficient and specific wear rate of self-lubricating composite were reduced by 25. 4% and 65. 3%,respectively,as compared to the pure LLDPE.