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.
The preparation of monodisperse colloidal microlatex particles of polystyrene and poly(styrene butene diacid) by the use of microwave radiation and under normal ambient pressure is reported. There is no surfactant in the system.The total synthesis time has been reduced from more then 10h(conventional method) to less than 1 h(microwave mothod). The dynamic experimental results indicate that the reaction proecss is very sharp in comparison with conventional polymerization. No constant rate stage existed.
