THE ELECTROPOLYMERIZATION OF POLY(STYRENE-CO-4-CARBOXYPHENYL MALEIMIDE) COATINGS ONTO STEEL

Electropolymerization can be used to produce uniform and pin-hole free coatings on surfaces of complex shapes, due to the intrinsic characte ristic of the process. In this article, the electrocopolymerization be havior of 4-carboxyphenyl maleimide (4CPMI) with styrene onto a steel surface is reported. The polymerization mechanism is by free radical, as might be expected for an aqueous reaction environment. Experimental results suggest that initially a charge transfer complex forms betwee n styrene and 4CPMI, which is much more reactive than either of the tw o monomers. Alternating copolymers are always obtained at low conversi on, even with significant changes in the monomer feed compositions. Be cause of the incorporation of rigid imide rings into the copolymer bac kbone, the coating formed has very good thermal properties and is thus a potential candidate for high-temperature applications. Furthermore, the copolymer dielectric constant is comparable to that of commercial polyimides, making it attractive for use in electrical and electronic insulation applications. (C) 1996 John Wiley & Sons, Inc.