Synthesis and characterization of silicone modified acrylic resin and its uses in the emulsion paints

Abstract

The acrylate-silicone emulsions were prepared by emulsion copolymerization of m ethyl methacrylate (MMA), butylacrylate (BA), methacrylic acid (MAA) with vinyl triethoxysilane (VTES), and auxiliary agents at 85 degrees C in the presence of potassium persulphate (KPS) as initiator. Alkylphenol ethersulphate and Arkupal N-300 were used as anionic and non-ionic emulsifiers, respectively. The resulting copolymers were characterized by using Fourier transform infrared spectroscopy (FTIR). Thermal properties of the copolymers were studied by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The morphology of copolymers was also investigated by scanning electron microscopy (SEM) and then the effects of temperature, agitation speed, initiator and VTES concentrations on polymerization rate are discussed. The obtained polymers had high solid content (43%) and were used in the emulsion paints as a binder. The experimental results show that these polymers supply very useful properties such as excellent storage stability, UV light stability, washing and abrasion resistance with good brushing in the above mentioned paints. The calculations of monomer conversion versus time histories and monomer conversion to polymer indicate that by increasing the VTES concentration, the polymerization rate and the number of polymer particles decrease, respectively.