N-Bromosuccinimide (NBS) was used as a thermal iniferter for the initiation of the bulk polymerizations of methyl methacrylate, methyl acrylate, and styrene. The polymerizations showed the characteristics of a living polymerization: both the yields and the molecular weights of the resultant polymers increased linearly as the reaction time increased. The molecular weight distributions of the polymers were 1.42-1.95 under the studied conditions. The resultant polymers could be used as macro-iniferters to reinitiate the polymerization of the second monomer. The copolymers poly(methyl methaerylate)-b-polystyrene and polystyrene-b-poly(methyl methacrylate) were obtained and characterized. End-group analysis of the resultant poly(methyl methacrylate), poly(methyl acrylate), and polystyrene confirmed that NBS behaved as a thermal iniferter. (c) 2005 Wiley Periodicals, 1nc.