PARTICAL SIZE EVOLUTION IN SURFACTANT-FREE EMULSION COPOLYMERIZATION OF STYRENE AND METHYL METHACRYLATE IN AQUEOUS SOLUTION OF POLY(ETHYLENE GLYCOL): PARTICAL SIZE EVOLUTION IN SURFACTANT-FREE EMULSION COPOLYMERIZATION OF STYRENE AND METHYL METHACRYLATE IN AQUEOUS SOLUTION OF POLY(ETHYLENE GLYCOL)