Electrochemical codeposition of PMMA particles with zinc

Zinc matrix composite coatings containing polymethyl methacrylate (PMMA) particles were electrodeposited from an aqueous acidic (pH 2.0 and 4.0), lignosulfonate solution of zinc sulfate on low-carbon steel substrates, under galvanostatic, either constant or pulse current, plating conditions at current densities of 2 and 20 A dm−2. The effect of particle inclusion on the deposit electrocrystallization was investigated by X-ray diffraction and scanning electron microscopy. The observed dependence of the PMMA content of the deposits on bath pH and applied current density was illustrated in terms of the particle surface charge variation and their interaction with the growing metal phase. The corrosion resistance of the composite coatings was evaluated by Tafel analysis.