Résumé
Four different xanthates containing either phosphonate or bisphosphonate moieties were synthesized with high degree of purity. These xanthates were used as chain transfer agents (CTA) in the RAFT/MADIX polymerization of vinyl acetate (VAc) to prepare end-capped poly(VAc). The rate of VAc polymerization in the presence of these new CTAs was shown to be similar to that obtained with conventional xanthate, that is, (methyl ethoxycarbonothioyl) sulfanyl acetate. Good control of VAc polymerization was also obtained since the molecular weight increased linearly with monomer conversion for each phosphonate-containing xanthate. Low-PDI values were obtained, ascribed to efficient exchange during RAFT/MADIX polymerization. Cex value was therefore calculated to about 25, based on RAFT/MADIX of VAc in the presence of rhodixan A1/ VAc adduct.