Studies of arenediazonium salts as a new class of electropolymerization initiator

Electropolymerization holds great potential as a novel process for applying surface coatings onto a variety of substrates. Cathodic electropolymerizat ion has been conducted successfully on metal substrates using initiation sy stems, such as sulfuric acid and potassium persulfate. However, each of the se initiation systems has its own deficiency. This provided the motivation for investigating arenediazonium salts as a new class of cathodic electropo lymerization initiators. Our studies found that arenediazonium salts can be easily reduced at reduction potentials lower than that of water to generat e initiating free radicals. The reduction efficiency is very high. A copoly mer of methyl acrylate and acrylonitrile has been polymerized onto steel su rfaces using one of these salts, 4-methyl benzenediazonium tetrafluoroborat e, as initiator. Cyclic voltammetry and reflection absorption infrared spec troscopy (RAIRS) studies suggest a strong interaction exists between the in itiator and the substrate, which can potentially enhance coating adhesion. (C) 1999 John Wiley & Sons, Inc.