Controlled/living free-radical polymerization in the presence of benzyl 9H-carbazole-9-carbodithioate under 60CO γ-ray irradiation

Free-radical polymerization of vinyl monomers under (60)Co gamma-ray irradiation in the presence of benzyl 9H-carbazole-9-carbodithioate (BCCDT) have been studied. The polymers obtained were characterized by gel permeation chromatography (GPC) and (1)H nuclear magnetic resonance ((1)H NMR) spectroscopy. The results for the polymerization of methyl acrylate show that the molecular weight increases linearly with monomer conversion, that the molecular weight distribution is fairly narrow (even equal to 1.01) and that a linear relationship exists between 1n([M](0)/[M]) and polymerization time. All the evidence suggests that BCCDT is a good control agent and that the polymerization has excellent living characteristics. For styrene, the polymerization is a controlled process, although it is very slow, whereas the polymerization of methyl methacrylate is uncontrolled. To the best of our knowledge, this is the first time that dithiocarbamate has been used in gamma-ray initiated living free radical polymerization.