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

摘要

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.