ATRP-template dispersion polymerization of methacrylic Acid/PVP

ATRP-template dispersion polymerization of methacrylic acid (MAA) on the template of polyvinyl pyrrolidone (PVP K-30) was carried out in the aqueous solution by using methyl 2-bromopropionate (MBP)/CuCl/2,2′-bipyridine (bpy) as the initiation system. The scanning electron microscopy (SEM), dynamic light scattering (DLS) and gel permeation chromatography (GPC) were employed for evaluating the results of polymerization. As a result, the minimonomer droplets formed due to the H-bond interaction of PVP-MAA. The stability of droplets was dependent on pH and the concentrations of both PVP and MAA. When pH 4.5, the droplets were not observable by DLS. In order to prepare the stable latex, the concentration of PVP should be lower than 9 wt%, whilst the concentration of MAA should be lower than 5.5 wt%. The optimum condition was pH 2.4, PVP 4.76 wt% and MAA 5 wt%, by which the stable latex of ca. 50 nm nanoparticles of PMAA/PVP was prepared by ATRP polymerization and simultaneously the molar mass of PVP was duplicated by PMAA according to GPC diagrams. In contrast, by using AIBN, KPS and KPS-Na2SO3 redox initiation system, the coagulum accompanying with the larger molar mass of PMAA was obtained, irrespective of pH and concentrations of PVP and MAA.