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 electro‐polymerized poly (N,N‐dimethylacrylamide) deposited on the surface of the graphite fiber working electrode. The formation of poly (N,N'dimethyl acrylamide) was inhibited by hydroquinone. The addition of about 0.05 moles of hydroquinone to the reaction solution resulted in about a 90% decrease in the weight gain of fibers, 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 concerntration, raised to the power of 1.3, 0.42, and 0.07, respectively, that is, Rp ∝ [M]1.3‐Cd0.42 [H2SO4]0.07. A mathematical model, based upon free radical polymerization kinetics, is discussed.