The unsaturated dimer of methyl acrylate [CH2=C(CO2CH3)CH2CH2CO2CH3, or MAD] was copolymerized with various monomers to prepare copolymers bearing the to-unsaturated end group [CH2=C(CO2CH3)CH2-] arising from beta fragmentation of the MAD propagating radical. Copolymerizations of ALA D with cyclohexyl and n-butyl acrylate resulted in copolymers with omega-unsaturated end groups, and increasing the temperature up to 180degreesC resulted in an increase in the rate of 0 fragmentation of MAD radicals relative to propagation. Only a small amount of unsaturated end groups was introduced by copolymerization with ethyl methacrylate (EMA), and the EAM content in the copolymer increased with temperature. These findings could be explained by the reversible addition of the poly(EMA) radical to MAD. The copolymerization with ethyl a-ethyl acrylate (EEA) did yield a copolymer containing unsaturated end groups with MAD units as part of the main chain, although the steric hindrance of the ethyl group suppressed homopropagation and crosspropagation of EEA, resulting in low polymerization rates. Therefore, the copolymerization of MAD with acrylic esters at high temperatures was noted as a convenient route for obtaining acrylate-MAD copolymers bearing unsaturated end groups at the omega end (macromonomer). (C) 2003 Wiley Periodicals, Inc.