润滑剂对PE木塑复合材料性能的影响

Effect of Lubricants on Properties of PE Wood Plastic Composites

以高密度聚乙烯为基体,木粉为填料,分别采用硬脂酸(HSt),HSt/乙撑双硬脂酸酰胺(EBS)复合物以及复合脂肪酸盐3种不同润滑剂体系,通过微型注塑和挤出成型制备了3种木塑复合材料(WPC),研究了3种润滑剂体系对WPC力学性能、线性热膨胀系数(CLTE)、熔融结晶行为及热稳定性的影响。结果表明,添加HSt和HSt/EBS复合物的WPC拉伸性能相差不大,而添加复合脂肪酸盐的WPC拉伸强度和拉伸弹性模量相对较低,断裂伸长率相对较高。使用温度为–40～40℃时,添加HSt的WPC CLTE最高,添加复合脂肪酸盐的WPC最低;而使用温度为40～80℃时,添加HSt的WPC CLTE最低,添加HSt/EBS复合物的WPC最高。润滑剂对WPC的熔融温度和结晶温度影响不大,其中添加HSt的WPC结晶度最高,添加HSt/EBS复合物的WPC结晶度最低。热重分析表明,与其它两种润滑剂相比,添加HSt/EBS复合物的WPC热分解温度最高,失重率最小,具有最好的热稳定性。

Taking high-density polyethylene as plastic matrix,wood powder as filler,stearic acid(HSt),HSt/ethylene distearate amide(EBS)compound and compound fatty acid salt as three lubricating systems,the three kinds of wood plastic composite(WPC)were prepared by micro injection and extrusion molding equipment.The effects of the three lubricating systems on the mechanical properties,coefficient of linear thermal expansion(CLTE),melting and crystallization behaviors and thermal stability of WPC were studied.The results show that the tensile properties of WPC with HSt and HSt/EBS are similar,the tensile strength and modulus of elasticity of WPC with compound fatty acid salt are relatively low,but the elongation at break is relatively high.When the using temperature is–40-40℃,the linear thermal expansion coefficient(CLTE)of WPC with HSt is the highest,the CLTE of WPC with compound fatty acid salt is the lowest,but when the using temperature is 40-80℃,the WPC with HSt has the lowest CLTE and the WPC with HSt/EBS has the highest CLTE.The three lubricating systems have slight influences on the melting and crystallization temperature of WPC,the crystallinity of WPC with HSt is the highest and the crystallinity of WPC with HSt/EBS is the lowest.Thermogravimetric analysis show that,compared with the other two lubricants,the WPC with HSt/EBS has the highest decomposition temperature and the lowest weight loss rate,which indicates that the WPC has the best thermal stability.