DC electrical conduction phenomena in fibre reinforced composites

A programme of experiments designed to examine several aspects of the DC conduction properties of metal fibre filled thermoplastics, is described. It is shown that the inclusion of less than 1% volume fraction of stainless steel fibres in a polypropylene matrix is sufficient to realise volume resistivities of less than In em. The application of percolation models of conductivity based on the assumption of kinked or curved fibre trajectories are considered, and it is shown that non-uniform sample heating caused by poor particle dispersion can be readily identified by infrared imaging. Model samples consisting
of two fibres embedded in a thin layer of polypropylene were subjected to simultaneous electrical measurements, thermal imaging, and optical microscopy. The data suggested that spherulite boundaries constitute
the most likely path of charge transfer between the fibres and that the dielectric strength of a spherulite is many times that of the bulk polymer.

Citation:
Bridge, B., Folkes, M.J., and Jahankhani, H (1989) 'DC electrical conduction phenomena in fibre reinforced composites' Institute of Physics Conference Series, 89(8), 307-312.