Use of methyl 2-(bromomethyl)acrylate as a chain-transfer agent to yield functionalized macromonomers via conventional and living radical polymerizations

The chain-transfer constants of methyl (2-bromomethyl)acrylate (MBrMA) in bulk polymerizations of methyl methacrylate (MMA) and styrene were determined at 70 degrees C using both the Mayo method (1/DPn as well as 2/DPw) and the chain-length-distribution procedure (Lambda). The C(MBrMA)values using 2/DPw and Lambda were consistent, i.e., 1.28 and 1.20 for MMA and 11.44 and 10.92 for styrene, respectively. MBrMA was used as a chain-transfer agent in the emulsion polymerization of MMA to yield an a-bromo-functionalized macromonomeric latex ([M-n] = 9.6 x 10(3) g mol(-1); PDI = 1.80), which was subsequently copolymerized with styrene to yield the corresponding poly(styrene-graft-MMA) copolymer. MBrMA was used as an addition-fragmentation agent in the living radical polymerization of MMA mediated by copper(I) bromide/N-(n-octyl)-2-pyridylmethanimine In situ addition of a 5-fold equivalent of MBrMA and Cu(0) to this polymerization quenched the reaction and transformed the omega-bromide into the methacrylate-based macromonomer quantitatively.