Controlling Morphology, Electrical, and Mechanical Properties of Polymer Blends by Heterogeneous Distribution of Carbon Nanotubes

Electrical and mechanical properties of some new composites made of copolyamide/polypropylene/carbon nanotubes (CPA/PP/CNTs) in different ratios, in correlation with their morphology, were investigated. The polymer blends based on polypropylene and low melting point copolyamide filled with CNTs were prepared by two methods. In the first procedure, CNTs were orderly distributed into the heterogeneous polymer matrix where filler occupied only one polymer component creating a highly branched conductive phase that provides a low value of the percolation threshold. In second case, CNTs were randomly distributed in the heterogeneous polymer matrix created by the blend CPA/PP yielding in a higher value of percolation threshold. Four factors influence on the distribution of filler, namely: thermodynamics, kinetics, chemical factor, and processing. Both electrical and mechanical properties are defined by spatial distribution of the conductive nanofiller in the polymer blend. (C) 2015 Society of Plastics Engineers