纳米碳形貌对纳米碳/聚乙烯导电复合材料性能的影响

Effect of nano carbon shape on the properties of nano carbon/polyethylene conductive composites

分别以纺锤形碳酸钙表面改性的二维片状石墨烯微片(CGM)和多壁碳纳米管(MWCNTs)作为导电剂填充改性聚乙烯(PE)制备导电复合材料。重点研究了二维或一维纳米碳/PE复合材料形成导电网络时力学与电学性能。CGM/PE或MWCNTs/PE复合材料达到抗静电要求时CGM的质量分数为8wt%,而MWCNTs的质量分数为1wt%。填充8wt%CGM的复合材料表现出优异的综合性能,而填充0.5wt%MWCNTs的复合材料综合力学性能达到最大值还未能达到抗静电要求,达到抗静电要求时MWCNTs/PE复合材料的综合力学性能出现下降趋势。通过形貌及流变学分析了复合材料不同的力学与电学性能的微观作用因素。CGM/PE复合材料流变渗流阈值与导电渗流阈值存在比较好的相关性,MWCNTs/PE复合材料达到流变渗流阈值还不能形成导电网络。结果表明,与二维CGM相比,一维MWCNTs不易均匀分散于聚合物基体中,并降低MWCNTs/PE复合材料的力学性能。

Conductive polyethylene（PE）composites were prepared by using two-dimensional flaky graphene microparticles modified on the surface of spindle shaped calcium carbonate（CGM）and multi-walled carbon nanotubes（MWCNTs）filled PE.The mechanical and electrical properties of the compound system where the conductive network forms by filling with two-dimensional or one-dimensional nano carbon composites were studied.When they arrive at antistatic composite,the mass fraction of the CGM and MWCNTs are 8 wt% and 1 wt%,respectively.The composite properties of 8 wt% CGM show excellent performance,while comprehensive mechanical properties of the MWCNTs/PE composite filled with 0.5 wt% MWCNTs reach maximum,when arriving at antistatic appears to decline.The microscopic action factors of different mechanical and electrical properties of nano carbon composites were analyzed by morphology and rheology.There is a good correlation between rheological seepage threshold and conductive seepage threshold for CGM/PE composite.However,the MWCNTs/PE composite that can reach the threshold of rheological seepage can not form conductive network.The results show that one-dimensional MWCNTs is not easily dispersed in the polymer matrix,and reduces the mechanical properties of MWCNTs/PE composites compared with two-dimensional CGM.