Electrical behavior of high density polyethylene/ZnO nano-composites

High density polyethylene (HDPE)/ZnO composites containing a wide range of ZnO content (1-60 vol%) were prepared by melt compounding. ZnO powders with sizes of ∼ 200 nm and ∼ 2 μm were employed as reinforcing fillers. The effects of the size and filler particle content as well as annealing treatment on the dielectric and conducting properties of the HDPE/ZnO composites were examined. The results showed that the dielectric constant of MDPE/ZnO composites increased gradually with an increase of the ZnO content. The resistivity of HDPE/ZnO composites can be described satisfactorily by the interparticle distance of filled particles. This behavior is interpreted in terms of tunneling of the electrons through the insulating layer of polymer separating two neighboring ZnO fillers. The correlation between the structure and electrical property of the composites is discussed.