聚丙烯共混改性体系力学性能研究

Mechanical Properties of Modified Polypropylene Blends

首先分别采用乙烯 -辛烯共聚物弹性体 (POE)、有机改性的天然累托石粘土 (OREC)与经过表面处理的两种晶须 :硼酸铝、钛酸钾与均聚聚丙烯 (PP)进行二元熔融共混改性 ,其次采用两种改性剂对PP进行三元共混改性。结果表明 :弹性体虽能增加聚丙烯的韧性 ,但是其拉伸强度有相当大下降 ,粘土虽能同时提高聚丙烯的韧性与强度 ,但是增韧的幅度有限 ,晶须增强、增韧效果较差。POE与OREC对PP有协同增强增韧作用 ,三元共混体系POE/OREC/PP在适当配比时的力学性能有较大幅度的改善 ,其冲击性能比纯PP提高 2 0 4%,比二元体系POE/PP提高15 .6 %,拉伸强度比纯PP下降 15 .6 %,比二元体系POE/PP提高 2 2 .6 %。

POE (polyolefin elastomer)/PP, OREC(organic rectorite)/PP, and whiskers(potassium titanate(TiK) and aluminium borate(BAl)/PP composites were prepared by melt blending process, and then the POE/OREC/PP, POE/TiK/PP, and POE/BAl/PP were prepared.The results show that POE can improve the impact strength of PP, but tensile strength was greatly decreased. Clay can upgrade the toughness and strength of PP simutaneously, but the increase extent is finite. The effect of reinforcement and toughness of whisker is bad. POE and OREC have synergistic effect of reinforcement and toughness on PP. Mechanical properties of POE/OREC/PP with proper composition were boosted immensely, and its impact strength was 204 % on pure PP and up 15.6 % on POE/PP respectively; its tensile strength was down 15.6 % on PP and up 22.6 % on POE/PP.