| Abstract: | Block copolymers were synthesized by a sequential free radical polymerization method with the use of di-t-butyl-4,4′-azobis(4-cyanoperoxyvalerate) as the trifunctional initiator. The polymerizations were carried out in two stages. First, the poly(methyl methacrylate) and poly(butyl methacrylate) polymeric initiators were synthesized by activating, at room temperature, the perester groups of the initiator with tetraethylenepentamine. For the second stage, the reaction ingredients were pre-emulsified, then the azo groups of these polymeric initiators were activated thermally in the presence of either styrene or p-methylstyrene. It was found that the reaction in the emulsion particles followed bulk kinetics, although the average size of the particles was small, 50–100 nm. |
