Xanthates as Chain-Transfer Agents in Controlled Radical Polymerization (MADIX): Structural Effect of the O-Alkyl Group

✍ Scribed by Mathias Destarac; Wojciech Bzducha; Daniel Taton; Isabelle Gauthier-Gillaizeau; Samir Z. Zard

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 118 KB
• Volume: 23
• Category: Article
• ISSN: 1022-1336
• DOI: 10.1002/marc.200290002

✦ Synopsis

Abstract

The capability of three chain‐transfer agents, O‐alkyl‐S‐(1‐ethoxycarbonyl)ethyl xanthates (CH~3~CHCO~2~C~2~H~5~)S(CS)OZ′, to control the free‐radical polymerization of styrene and ethyl acrylate by the MADIX process was examined. The reactivity of the xanthates varied according to the following trend: Z′  CH~2~CH~3~ < CH~2~CF~3~ < CH[P(O)(OEt)~2~]CF~3~. This change in reactivity allowed a lowering of the polydispersity index from 2.0 for Z′  CH~2~CH~3~ to 1.15 for Z′  CH[P(O)(OEt)~2~]CF~3~ in the case of the polymerization of styrene.
Evolution of M~w~/M~n~ with conversion during the polymerization of ethyl acrylate in the presence of xanthates X~1~, X~2~ and X~3~. Reaction conditions: [EA]~0~ = 4.6 M, [X]~0~ = 5.75 × 10^−2^ M, [AIBN]~0~ = 1.72 × 10^−3^ M ; T = 80 °C ; solvent: toluene.

magnified imageEvolution of M~w~/M~n~ with conversion during the polymerization of ethyl acrylate in the presence of xanthates X~1~, X~2~ and X~3~. Reaction conditions: [EA]~0~ = 4.6 M, [X]~0~ = 5.75 × 10^−2^ M, [AIBN]~0~ = 1.72 × 10^−3^ M ; T = 80 °C ; solvent: toluene.