THIOL-ENDED POLYETHYLENE OXIDE AS REACTIVE STABILIZER FOR DISPERSION POLYMERIZATION OF STYRENE

Radical dispersion polymerization of styrene in aqueous ethanol soluti ons was performed in the presence of a new reactive polyethylene oxide stabilizer with thiol end groups. This reactive stabilizer was compar ed to the more conventional poly (N-vinyl pyrrolidone). Particles size distribution, molecular weights and kinetics were investigated, Monod ispersed polymer particles with diameter-in the range 200-2000 nm were obtained depending on the amount of stabilizer used, In all cases, th e polyethylene oxide (PEO) sequence of the dispersant was partly incor porated at the surface of the latex particles, but the grafting yield of polyethylene oxide chains was always limited and did not exceed 15% . Part of the stabilizer being unreacted or reacted with low molecular weight polystyrene remained in the continuous phase.