Dispersion polymerization using hydroxy-functional macroazoinitiators as an inistab

Abstract

Hydroxy-functional macroazoinitiators with central azo unit have been synthesized by atom transfer radical polymerization of 2-hydroxyethyl methacrylate or 2-hydroxypropyl methacrylate in methanol. The mean degrees of polymerization of the polymer chains beside the azo group were fixed at 30 and 60. Proton nuclear magnetic resonance (1H NMR) and gel permeation chromatography were used to characterize the macroazoinitiators in terms of their chemical structure, molecular weight, and polydispersity, respectively. Dispersion polymerizations of styrene using the hydroxy-functional macroazoinitiators as an inistab (initiator + colloidal stabilizer) in 2-propanol or 2-propanol/water media resulted in submicrometer-sized polystyrene latex particles with hydroxy-functional polymer hair. Electron microscopies, Fourier transform infrared spectrometer, thin layer chromatography, and 1H NMR were used to characterize the particles in terms of their morphologies, particle sizes, and their distributions and chemical compositions. The synthesized particles behaved as an effective particulate emulsifier for the stabilization of oil-in-water emulsions. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011