More particularly, monoethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, cthacrylic acid and crotonic acid, monoethylenically unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and citraconic acid, and monoethylenically unsaturated tricarboxylic acids such as aconitic acid can be employed, as can their halogen-substituted (e.g., flu