Xanthate-Mediated Controlled/Living Free-Radical Polymerization under 60Co γ-Ray Irradiation: Structure Effect of O-Group

✍ Scribed by Daoben Hua; Junpeng Xiao; Ruke Bai; Weiqi Lu; Caiyuan Pan

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 134 KB
• Volume: 205
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200400131

✦ Synopsis

Abstract

Summary: The free‐radical polymerizations of vinyl monomers have been studied under ^60^Co γ‐ray irradiation in the presence of S‐benzyl O‐ethyl dithiocarbonate (X1), S‐benzyl O‐phenyl dithiocarbonate (X2), S‐benzyl O‐2‐naphthyl dithiocarbonate (X3), S‐benzyl O‐(4‐methoxyphenyl) dithiocarbonate (X4), and methyl 4‐{[(benzylthio)carbonothioyl]oxy}benzoate (X5), respectively. The results indicate that the polymerizations of methyl acrylate (MA) reveal good living characteristics in the presence of X2, X3, X4, and X5 with O‐aryl groups, which play an important role in polymerization behavior; large aryl groups lead to slow polymerization. In contrast, the polymerizations with X1 couldn't be controlled and the obtained polymers had a broad‐molecular‐weight distribution or were even cross‐linked. In addition, it was observed that the polymerization of styrene with X2 was a controlled process though it was very slow, and the uncontrolled polymerization of methyl methacrylate (MMA) occurred under γ‐ray irradiation. To the best of our knowledge, this is the first report of xanthates being used as control agents in controlled/living free radical polymerization under γ‐ray irradiation.

The structures of the xanthates used here.

magnified imageThe structures of the xanthates used here.