Phase separation during the chemical blending of polybutadiene/polystyrene blend

Abstract

Phase separation behavior of the chemical blending of the polybutadiene(PBD)/polystyrene(PS) was investigated by the light scattering technique. Polybutadiene was dissolved in the styrene monomer and the polymerization of the styrene monomer was carried out thermally in the presence of the dissolved polybutadiene. The effect of the PBD composition, synthesis temperature and the PS crosslink density on the phase separation behavior were analyzed. The mixture of PBD/PS/styrene monomer showed UCST(upper critical solution temperature) character. It was found that the phase separation was proceeded by the nucleation and growth mechanism in the early stage of polymerization. The time(t) denpendence of the domain correlation length(dm) could be represented by a power law in the late stage of the phase separation. The crosslinking of PS hindered phase separation in the coalescence process.