PROCESSING, STRUCTURE, AND ELECTRICAL PROPERTIES OF METAL-FILLED POLYMERS

Abstract

Polymer-metal composites (PMCs) based on polyethylene (PE) and polyoxymethylene (POM) and on the blend PE/POM filled with dispersed iron or copper were prepared. Composites were produced by several methods: (1) extrusion of homopolymer (PE or POM) filled with iron, (2) extrusion of the blend PE/POM filled with iron, (3) compression molding of PE filled with dispersed copper, and (4) extrusion of PE filled with copper. The method of processing was found to influence the percolation behavior of electrical conductivity. Polymer-metal composites obtained by extrusion were characterized by low values of conductivity and high values of percolation threshold phi (c), whereas composites based on the polymer blend showed low values of phi (c). These differences are caused by the specific structure of composites based on the polymer blend. The metal filler was involved only in the POM phase and forms an ordered structure in the volume of the polymer matrix. PE-Cu composites produced by compression molding showed the best electrical parameters. A structure model explaining these results is proposed.