A stable emulsion of poly(WPSF-co-butyl acrylate) based on butyl acrylate, waste polystyrene foam was synthesized through emulsion polymerization using sodium dodecyl Sulfate and octyl phenyl polyoxyethylene ether as surfactant, ammonium persulfate and sodium hydrogen bisulfate as mixed redox initiator, under ultrasound irradiation in the absence of inert gas. The effects of various copolymerization conditions on the monomer conversion were reported. The copolymers were characterized by means of IR, (HNMR)-H-1, and gel permeation chromatography. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 3196-3201, 2009