Carboxylated polystyrene particles were prepared by the batch emulsion polymerization of styrene (Sty) with 4-vinylbenzoic acid (VBA) in the absence of an emulsifier with K2S2O8 as a free-radical initiator. The effect changes in the ratio of potassium hydroxide to VBA and the concentration of VBA to Sty on the kinetics, monomer conversion, distribution of carboxyl groups, and particle size distribution were analyzed. The stability of the latices was evaluated. (c) 2006 Wiley Periodicals, Inc.