增容剂对PE—HD／PC／CB导电复合材料PTC效应的影响

摘要

研究了增容剂马来酸酐接枝聚乙烯（PE-g-MAH）、乙烯-醋酸乙烯酯（EVA）、苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）对高密度聚乙烯（PE-HD）／聚碳酸酯（PC）／炭黑（CB）复合材料导电性能的影响。结果表明，加入增容剂有利于增强复合材料的正温度系数（PTC）效应，其中嵌段共聚物SBS对复合材料PTC效应的改善效果相对较好，SBS含量为4％（质量分数，下同）时，复合材料的PTC强度最高，比未添加时提高了14．3％；接枝共聚物PE-g-MAH的加入对复合材料PTC效应的增强效果弱于SBS；无规共聚物EVA的加入对负温度系数（NTC）现象具有明显的抑制作用，使复合材料的NTC强度从0．3下降至0．08。%Effects of three kinds of compatibilizers, maleic anhydride grafted polyethylene （PE-g- MAH）, ethylene vinyl acetate （EVA） and styrene-butadiene-styrene block copolymer （SBS）, on electrical properties of high-density polyethylene （PE-HD）/polycarbonate （PC） /carbon black （CB） composites were studied. It showed that the addition of compatibilizers to PE-HD/PC/CB composites promoted the positive temperature coefficient （PTC）, and the modification effect of SBS was the best among the three compatibilizers. When the content of SBS was 4 wt 0%, the PTC intensity of the composite increased by 14. 3 % based on neat PE-HD/PC/CB composite. The promotion of PTC intensity by PE-g-MAH was less than that of SBS. EVA had the advantage to inhibit the negative temperature coefficient （NTC） phenomenon, the NTC intensity of the composites decreased from 0. 3 to 0.08.