Electrical properties and morphology of carbon black-filled HDPE/EVA composites

Authors

  • Quan-Quan Yang,

    1. School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, People's Republic of China
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  • Ji-Zhao Liang

    Corresponding author
    1. School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, People's Republic of China
    • School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, People's Republic of China
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Abstract

The sensitive effect of weight ratio of the high-density polyethylene (HDPE)/ethylene-vinylacetate copolymer (EVA) on the electrical properties of HDPE/EVA/carbon black (CB) composites was investigated. With the EVA content increasing from 0 wt % to 100 wt %, an obvious change of positive temperature coefficient (PTC) curve was observed, and a U-shaped insulator-conductor-insulator transition in HDPE/EVA/CB composites with a CB concentration nearby the percolation threshold was found. The selective location of CB particles in HDPE/EVA blend was analyzed by means of theoretical method and scanning electron micrograph (SEM) in order to explain the U-shaped insulator-conductor-insulator transition, a phenomenon different from double percolation in this composite. The first significant change of the resistivity, an insulator-conductor transition, occurred when the conductive networks diffused into the whole matrix due to the forming of the conductive networks and the continuous EVA phase. The second time significant change of the resistivity, a conductor-insulator transition, appeared when the amorphous phase is too large for CB particles to form the conductive networks throughout the whole matrix. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

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