Dispersion polymerization of polystyrene latex stabilized with novel grafted poly(ethylene glycol) macromers in 1-propanol/water

A novel hydrophilic macromer adapted for chemical grafting has been synthes ized. It consists of methyl-end-capped poly(ethylene glycol) functionalized with a urethane terminus. Dispersion polymerization of styrene in an alcoh ol/water medium in the presence of the macromer allows chemical grafting of the macromer to the surfaces of the developing polystyrene (PS) latex part icles. Scanning and transmission electron microscopies confirm the formatio n of spherical, submicron polystyrene particles. Transmission electron micr oscopy of films prepared from the latex particles also permits direct visua lization of the stabilizing macromer layer grafted on the PS particle surfa ces. Data acquired from proton nuclear magnetic resonance reveal a direct c orrelation between the concentration of macromer in the reaction mixture an d the amount grafted to the latex particles. Rheological techniques are emp loyed to (i) discern the stabilization efficacy of the macromer and (ii) id entify correlations between latex and flow characteristics.