Study on controlled/living free-radical polymerization of methyl acrylate in the presence of benzyl 9H-carbazole-9-carbodithioate under thermal condition

摘要

The polymerizations of methyl acrylate have been studied under thermal condition using benzyl 9H-carbazole-9-carbodithioate (BCCDT) as control agent. The obtained polymers were characterized by gel permeation chromatography (GPC), H-1 nuclear magnetic resonance (H-1 NMR) and MALDI-TOF mass spectra. The results at 60 degrees C show that the molecular weight of the polymer increases linearly with monomer conversion, the molecular weight distribution is fairly narrow (even inferior to 1.10), and there exists a linear relationship between In ([M](o)/[M) and polymerization time. It is worthy of being noticed that the narrow polyclispersities are comparable with those from living anionic polymerization. All of the evidences indicate that the polymerization is a good 'living' process. When the experiment is carried out at higher temperature, the polymerization rate is markedly faster with controlled polymerization characters except for a relatively broader polydispersity. The good control for free radical polymerization may be correlated with the large conjugation structure of carbazyl of BCCDT. (c) 2005 Elsevier Ltd. All rights reserved.