Methyl 2-[2,2,2-tris(methoxycarbonyl)ethyl]acrylate and methyl 2-[2,2,2-tris(ethoxycar-bony1)ethyllacrylate [M(TE)EA] were synthesized for the first time by the reaction of methyl 2-(bromomethyl)acrylate with the corresponding tris(alkoxycarbony1)methane in the presence of triethylamine at room temperature in 90 and 89% yields, respectively. Attempted homopolymerization of these particular acrylates did hardly occur. However, the radical produced by attack of the primary radical from 2,2'-azo-2,4,4-trimethylpentane at the /3carbon of M(TE)EA was detected via its 5-line ESR spectrum, and a similar spectrum was observed using tert-butyl peroxide as initiator. These findings imply that persistency of the adduct radical of M(TE)EA suppresses further propagation to high molecular weight polymer. Steric congestion of the adduct radical was shown by ESR spectral change at different temperatures. Copolymerization of M(TE)EA with methyl methacrylate proceeded at a slow rate and yielded products containing only 1,7 -2,7 units of M(TE)EA per polymer chain irrespective of comonomer composition. When the content of M(TE)EA was lower than 10 mol-Vo in the monomer mixtures of M(TE)EA with styrene and methyl acrylate, copolymers whose molecular weights decreased with an increase in M(TE)EA content in monomer mixture were obtained. The copolymerization rates were also reduced considerably with increasing content of M(TE)EA in the feed.