高密度聚乙烯/膨胀石墨导电复合材料的研究

Study on High Density Polyethylene/Expanded Graphite Conductive Composites

用溶液插层制备的马来酸酐接枝聚乙烯 /膨胀石墨 (EG) ( 60 /4 0 )作为EG母料 ,以不同用量、方法或条件与PE HD熔融共混后模压为板材 ,研究了复合材料的加工 -结构 -性能关系。结果表明 :熔体捏合或挤出时物料受剪切程度越小 ,材料中EG粒子的尺寸、形状比越大 ,粒子内部EG -聚合物复合结构的规整性也越好 ,材料的导电逾渗阈值就越低 ,定EG含量下的电导率σ就越高而拉伸强度 (σt)越低。

A compound of maleic anhydride grafted polyethylene (60 %) and expanded graphite (EG, 40 %) was first prepared via solution intercalation. The compound was subsequently melt-blended with high density polyethylene (PE-HD) in varied compositions and via different methods.The relationship between processing, structure and properties was studied by means of electrical conductivity and tensile strength measurements and SEM, OM observations. The results showed that the weaker the shear exerted during the melt kneading or extrusion, the larger the size and aspect ratio of EG particles, and thus the lower the percolation thresholds. At a certain EG content,lower shear resulted in higher conductivities but lower tensile strengths.