Universal Xanthate-Mediated Controlled Free Radical Polymerizations of the Less Activated Vinyl Monomers

The living free radical polymerizations of three less activated monomers (LAMs), vinyl acetate, N-vinylcarbazole, and N-vinylpyrrolidone, were successfully achieved in the presence of a disulfide, isopropylxanthic disulfide (DIP), using 2,2 '-azoisobutyronitrile (AIBN) as the initiator. The living behaviors of polymerizations of LAMs are evidenced by first-order kinetic plots and linear increase of molecular weights (M(n)s) of the polymers with monomer conversions, while keeping the relatively low molecular weight distributions, respectively. The effects of reaction temperatures and molar ratios of components on the polymerization were also investigated in detail. The polymerization proceeded with macromolecular design via interchange of xanthate process, where xanthate formed in situ from reaction of AIBN and DIP. The architectures of the polymers obtained were characterized by GPC, H-1 NMR, UV-vis, and MALDI-TOFMS spectra, respectively. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 5206-5214, 2010