RATE OF ELECTROPOLYMERIZATION OF N,N' DIMETHYL ACRYLAMIDE IN AQUEOUS SULFURIC-ACID-SOLUTION

Electropolymerization of N,N-dimethylacrylamide has been performed in aqueous sulfuric acid solution, using unsized AS-4 graphite fibers as the working electrode. The electropolymerized poly(N,N-dimethylacrylam ide) deposited on the surface of the graphite fiber working electrode. The formation of poly(N,N'dimethyl acrylamide) was inhibited by hydro quinone. The addition of about 0.05 moles of hydroquinone to the react ion solution resulted in about a 90% decrease in the weight gain of fi bers, in agreement with the proposed free radical mechanism of aqueous electropolymerization. The rate of electropolymerization varied with the initial monomer concentration, current density, and sulfuric acid concentration, raised to the power of 1.3, 0.42, and 0.07, respectivel y, that is, R(p) is-proportional-to [M]1.3-Cd0.42[H2SO4]0.07 . A mathe matical model, based upon free radical polymerization kinetics, is dis cussed.