Xanthate-Mediated Copolymerization of Vinyl Monomers for Amphiphilic and Double-Hydrophilic Block Copolymers with Poly(ethylene glycol)

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• 作者：Gwenaelle Pound ; Fr&eacute ; d&eacute ; ric Aguesse ; James B. McLeary ; Ronald F. M. Lange ; Bert Klumperman
• 刊名：Macromolecules
• 出版年：2007
• 出版时间：December 11, 2007
• 年：2007
• 卷：40
• 期：25
• 页码：8861 - 8871
• 全文大小：195K
• 年卷期：v.40,no.25(December 11, 2007)
• ISSN：1520-5835

文摘

Two xanthate end-functional poly(ethylene glycol)s (PEGs) were tested as macromolecular chain-transfer agents (macroCTA) in the reversible addition-fragmentation transfer-mediated polymerization of vinylacetate (VAc) and N-vinylpyrrolidone. The macroCTA leaving group played a determining role in the preparationof the block copolymers. PEG-b-PVAc and PEG-b-PVP diblock copolymers were obtained when the macroCTAhad a propionyl ester leaving group, whereas under the same experimental conditions the macroCTA with aphenylacetyl ester leaving group inhibited the polymerization. In situ ¹H NMR spectroscopy polymerizationswere performed with low molecular weight xanthate analogues to investigate the cause of inhibition. Blockcopolymers were prepared with the macroCTA which did not inhibit the polymerization and were characterizedvia size exclusion chromatography, high-performance liquid chromatography, and matrix-assisted laser desorptionionization time-of-flight mass spectrometry. The ability to produce narrowly distributed (PDI < 1.4) blockcopolymers end capped with a xanthate moiety with little to no homopolymer contaminant is presented.