Preparation of latexes with poly(methyl methacrylate) cores and hydrophilic polymer shells containing amino groups

Functional latexes with poly(methyl methacrylate) (PMMA) cores and amino-containing, water-soluble polymer shells were synthesized via direct graft copolymerization of methyl methacrylate from water-soluble polymers induced by a small amount of tert-butyl hydroperoxide (TBHP) at 80degreesC for 2 h. Amphiphilic graft copolymers and PMMA homopolymers were generated concurrently to form highly monodispersed latexes. The effects of water-soluble polymer containing different amino group, reaction temperature, TBHP concentration, molecular weight of the polymer and pH of the solution on conversion and grafting efficiency of the monomer and particle size were investigated. Transmission electron microscopic images of the PMMA/poly(ethyleneimine) (PEI) and PMMA/poly(allylamine) (PAA) particles clearly show well-defined core-shell morphologies, where PMMA cores are coated with either PEI or PAA shell. The amino-containing polymer shells were also confirmed with zeta-potential measurements. Furthermore, the amino-containing latexes can be produced with a solids content up to 22 wt.%. Thus, this method provides a commercially viable route to functional latexes.