Controlled cationic polymer particles prepared by dispersion polymerizations using poly(l-lysine) macromonomers as a stabilizer

Abstract

A novel poly(l-lysine) macromonomer was successfully prepared via a click reaction between vinyl benzyl azide and propargyl-terminated poly(l-lysine), and it was used as a functional stabilizer for the dispersion polymerization of styrene; narrowly distributed polystyrene particles were produced as a result, onto which cationic poly(l-lysine) chains were grafted. The resulting particles exhibited a pH-responsive dispersion behavior in aqueous solutions due to the properties of the poly(l-lysine) chains at the particle surface. It was found that the particle size and the surface density of the resultant particles could be varied by tuning the concentrations of the macromonomer, styrene, and initiator used in the initial solution of the dispersion polymerization. The poly(l-lysine) macromonomer was also found to be effective when used as a stabilizer for the dispersion polymerization of both methyl methacrylate and a styrene/acrylonitrile mixture.