Styrene (St)/butyl acrylate (BA) copolymers were prepared by. adding triethoxyvinylsilane (TEVS), trimethoxyvinylsilane (TMVS), and triphenylvinylsilane (TPVS), each one through emulsion copolymerization. The polymerization was performed with methacrylic acid and auxiliary agents at 80 degrees C in the presence of potassium peroxodisulfate as the initiator. Nonylphenol ethylene oxide-40 units (NP-40) and sodium lauryl sulfoacetate were used as nonionic and anionic emulsifiers, respectively. The resulting copolymers were characterized by using Fourier transform infrared spectroscopy. Thermal properties of the copolymers were Studied by using thermogravimetric analysis and differential scanning calorimetry. The morphology of copolymers was also investigated by optical microscopy, and then the effects of silicone kinds and concentrations on the properties of the St/BA emulsion copolymers were discussed. The obtained copolymers have high solid content (50 %) and can be used in emulsion paints as a binder. The comparison of three different vinyl silanes indicates that the TEVS influences on the copolymer properties more than the others. The calculations of monomer conversion and monomer conversion versus time histories indicate that by increasing the silicone concentration, the polymerization rate decreases. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 1037-1044, 2009