HDPE/MWNTs复合材料PTC性能的研究

Study on properties of HDPE/MWNTs composites

研究了高密度聚乙烯，多壁碳纳米管复合材料的电阻非线性正温度系数现象（PTC）．结果表明，高密度聚乙烯，碳纳米管复合材料的渗滤域值为3％（质量分数，以下同）左右；当MWNTs含量为8．5％时复合材料的PTC强度最大，且基本没有后NTC效应；经过16次的加热．冷却循环后复合材料有好的电阻率．温度重现性；对样品SEM分析表明MWNTs在复合材料中的分布均匀．

The non-linear positive temperature coefficient phenomenon of high-density polyethylene/multi walled carbon nano tubes composites was studied. The results showed that as the MWNTs concents reach to 3wt% （Percolation Threshold）, the electrical conductivity of the composites changes from insulator to semiconductor. While as the MWNTs concents reach to 8.5wt% , the HDPE/MWNTs composites become a good conductor, its resistivity of the composites increases abruptly when the temperature approaches melting point of the matrix, indicating an existence of positive temperature coefficient（PTC） effect and no the negative temperature coefficient（NTC）. It should be noted that the MWNTs is average distribute in the composites by the SEM images.