Toward Well-Controlled ab Initio RAFT Emulsion Polymerization of Styrene Mediated by 2-(((Dodecylsulfanyl)carbonothioyl)sulfanyl)propanoic Acid

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• 作者：Yingwu Luo ; Xiaoguang Wang ; Bo-Geng Li ; Shiping Zhu
• 刊名：Macromolecules
• 出版年：2011
• 出版时间：January 25, 2011
• 年：2011
• 卷：44
• 期：2
• 页码：221-229
• 全文大小：959K
• 年卷期：v.44,no.2(January 25, 2011)
• ISSN：1520-5835

文摘

Reversible addition鈭抐ragmentation chain transfer (RAFT) ab initio emulsion polymerization of styrene mediated by 2-(((dodecylsulfanyl) carbonothioyl) sulfanyl) propanoic acid was investigated with sodium dodecyl sulfate (SDS), poly(acrylic acid)₂₉-b-polystyrene₅ trithiocarbonate macro-RAFT agent (PAA₂₉-PSt₅-RAFT), and poly(acrylic acid)₂₉-b-polystyrene₅ diblock co-oligomer (PAA₂₉-PSt₅) as the surfactant, respectively. Polystyrene latex having controlled molecular weight, relatively low PD and narrow particle size distribution was obtained by postneutralizing PAA₂₉-PSt₅-RAFT and PAA₂₉-PSt₅. This result was in agreement with the superswelling hypothesis that superswollen oligomer-containing particles caused the colloidal instability in the early stage of RAFT emulsion polymerization with SDS as surfactant. The successes of PAA₂₉-PSt₅-RAFT and PAA₂₉-PSt₅ were due to the high interfacial tensions of the styrene/water/surfactant systems that suppressed the superswelling and thus improved the colloidal instability. A majority of the initial RAFT molecules appeared to be converted at a low monomer conversion due to the inhibition period.