Radical Emulsion Polymerization of n-Butyl Acrylate and Its Copolymerization with Acrylonitrile in the Presence of Crosslinker

Abstract

The batch emulsion polymerization of n-butyl acrylate (BA) and copolymerization of BA with acrylonitrile (AN) in the presence of divinylbenzene (DVB) or 1,6-hexamethylene diacrylate (HMDA) were investigated at 60°C using a water-soluble initiator. DVB was found to decrease both the rate of polymerization and particle size; this being more pronounced in homopolymerization systems. This is discussed in terms of the decrease of the monomer concentration in latex particles and transfer of radical activity from the particle interior to the particle surface or continuous phase. The entered radicals are supposed to be deactivated via the reaction with the residual vinyl groups of DVB in the particle interior. The hydrophilic AN monomer favored polymerization events in water and reduced the effect of DVB on the rate and particle size. The formation of the AN/BA copolymer enriched with BA was found to increase with DVB concentration. The DVB monomer favors the nucleation of micelles but suppresses kinetic events in the continuous phase. HMDA was found to be an inert crosslinking agent. This is ascribed to the formation of compact microgels due to the strong intramolecular crosslinking.