Using acetone-water as medium and 2,2′-azobisisobutyramidine dihydrochloride(AIBA) as cationic radical initiator, three emulsifier-free cationic copolymer nanoparticles were synthesized under microwave irradiation from styrene with methylmethacrylate, diacetoneacrylamide and β-hydroxyethyl-methacrylate respectively. The latexes were excellently stable. The particles were characterized by IR, TEM, LLS. The influence of comonomer content and hydrophilicity on the hydrodynamic radius of copolymer nanoparticles was discussed. The results indicated that the average of copolymer particle decreased with increase of the concentration and hydrophilicity of the comonomer.
