A variety of polymerizable aromatic sulfonium salts have been used to prepare water-soluble polymers with high cationic activity [31,32]. Typical of the monomers used is 1-[3-methyl-4-(vinylbenzyloxy)phenylltetrahydrothiophenium chloride (~); a number of similar sulfonium materials, based on vinylbenzene, allyl phenoxy compounds, substituted aromatic methacrylates, and so on, also are used. Those polymers having low molecular weight and low charge density are useful as surfactants or emulsifiers in polymerization of ethylenically unsaturated monomers (styrene, butadiene, acrylates, etc.); those with high molecular weight and high charge density serve as thickeners and flocculants. A useful characteristic is that the latex polymers made with these sulfonium salts are irreversibly converted by heating or drying to inert, nonionic residues without the formation of odorous byproducts.