Synthesis of Poly (Butadiene –g–Styrene) Core-Shell Latex for Use in Cement Modifying

Abstract

Abstract Polybutadiene–graft –polystyrene (PB-g -PS) latex with different ratios of polybutadiene to polystyrene were prepared via emulsion graft copolymerization method through grafting styrene onto polybutadiene latex using a redox initiator system. The PB macroradicals reacted with styrene to form graft copolymers. The effect of initiator concentration, reaction temperature, grafting monomer/polybutadiene weight ratios, and monomer dropping time on the conversion, grafting efficiency, degree of grafting, and mean particle diameter of graft copolymerization reaction were investigated. The grafting efficiency of PB-g-PS was determined by a solvent-extraction technique. Fourier transform infrared spectroscopy and nuclear magnetic resonance technique were used to confirm structure of the synthesized copolymers. Transmission election micrographs verified that the synthesized latex particles had a core –shell structure, which can be incorporated into cement as modifier.