The polymerizations of alpha-ethyl beta-N-(alpha'-methylbenzyl)itaconamates carrying (RS)- and (S)-alpha-methylbenzylaminocarbonyl groups (RS-EMBI and S-EMBI) with dimethyl 2,2'-azobisisobutyrate (MAIB) were studied in methanol (MeOH) and in benzene kinetically and with electron spin resonance (ESR) spectroscopy. The initial polymerization rate (R-p) at 60 degreesC was given by R-p = k[MAIB](0.58 +/- 0.05) [RS-EMBI](2.4 +/- 0.1) and R-p = k[MAIB](0.61 +/- 0.05) [RS-EMBI](2.3 +/- 0.1) in MeOH and R-p = k[MAIB](0.54 +/- 0.05)[RS-EMBI] (1.7 +/- 0.1) in benzene. The rate constants of initiation (k(d)f), propagation (k(p)), and termination (k(t)) as elementary reactions were estimated by ESR, where k(d) is the rate constant of MAIB decomposition and f is the initiator efficiency. The k(p) values of RS-EMBI (0.50-1.27 L/mol s) and S-EMBI (0.42-1.32 L/mol s) in MeOH increased with increasing monomer concentrations, whereas the k(t) values (0.20-7.78 X 10(5) L/mol s for RS-EMBI and 0.18-6.27 X 10(5) L/mol s for S-EMBI) decreased with increasing monomer concentrations. Such relations of R-p with k(p) and k(t) were responsible for the unusually high dependence of RP on the monomer concentration. The activation energies of the elementary reactions were also determined from the values of k(d)f, k(p), and k(t) at different temperatures. R-p and k(p) of RS-EMBI and S-EMBI in benzene were considerably higher than those in MeOH. RP of RS-EMBI was somewhat higher than that of S-EMBI in both MeOH and benzene. Such effects of the kinds of solvents and monomers on R P were explicable in terms of the different monomer associations, as analyzed by H-1 NMR. The copolymerization of RS-EMBI with styrene was examined at 60 degreesC in benzene. (C) 2003 Wiley Periodicals, Inc.