ELECTROCHEMICAL PROCESS FOR PREPARING CONTINUOUS GRAPHITE FIBER THERMOPLASTIC COMPOSITES

An electrochemical process for preparing thermoplastic matrix-graphite fibre composites has been developed. Graphite fibre poly(maleimide-co -styrene) matrix composites were prepared using unsized AS-4 graphite fibre preforms as the working electrode. Copolymers of a wide range of N-substituted maleimides and styrene were formed directly on the surf ace of the graphite fibres. The rate of electrocopolymerization varied with the electrocopolymerization parameters, such as the comonomer co ncentration, current density, supporting electrolyte concentration, el ectropolymerization time, nature of the solvent, solvent/dilute sulfur ic acid ratio and the structure of the maleimide. Graphite fibre prefo rms preimpregnated with the electropolymerized thermoplastic matrices were processed into unidirectional composite laminates. The electrosyn thesized thermoplastic matrix composites showed excellent physical and mechanical properties.