BULK AND EMULSION COPOLYMERIZATIONS OF N-BUTYL ACRYLATE AND POLY(METHYL METHACRYLATE) MACROMONOMER

Bulk and emulsion copolymerizations of an omega-unsaturated poly(methy l methacrylate) (PMMA) macromonomer with n-butyl acrylate (n-BA) were investigated. The reactivity of PMMA macromonomer in bulk copolymeriza tion with n-BA was found to be lower than that of methyl methacrylate monomer with n-BA. The incorporation of PMMA macromonomer into poly(bu tyl acrylate) (PEA) latex particles by miniemulsion copolymerization w as proved by high performance liquid chromatography-silica adsorption spectroscopy. Dynamic mechanical studies showed that PMMA macromonomer was grafted to the PEA backbone, and the degree of grafting increased as the ratio of PMMA macromonomer to n-BA increased. Microphase separ ation of the PMMA macromonomer grafts was observed at higher ratio of macromonomer (higher or equal to 10% weight of macromonomer based on t otal polymer phase). The n-BA/PMMA macromonomer copolymer behaved comp letely differently from the physical blend of PEA and PMMA macromonome r particles of the same composition. (C) 1996 John Wiley & Sons, Inc.