Synthesis of Dendritic Polystyrenes from an Anionic Inimer

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• 作者：Wei Sun ; Junpo He ; Xiaojun Wang ; Chao Zhang ; Hongdong Zhang ; Yuliang Yang
• 刊名：Macromolecules
• 出版年：2009
• 出版时间：October 13, 2009
• 年：2009
• 卷：42
• 期：19
• 页码：7309-7317
• 全文大小：1006K
• 年卷期：v.42,no.19(October 13, 2009)
• ISSN：1520-5835

文摘

An anionic inimer (a monomer with an initiating site) is prepared by monoaddition of sec-butyllithium and 1,3-bis(1-phenylethenyl)benzene (MDDPE) in tetrahydrofuran (THF) at low temperature. The selectivity of monoaddition is high, yielding nearly quantitative formation of the inimer. The inimer is able to initiate the polymerization of styrene, forming different architectures of the products in THF and cyclohexane. In the former, linear product with larger-than-expected molecular weight is obtained whereas, when the solvent is switched from THF to cyclohexane, dendritic polymer is obtained through the copolymerization of the inimer and styrene. The resulting products are characterized by size exclusion chromatography equipped with a multiangle light scattering detector and a viscometer. Smaller radius of gyration and intrinsic viscosity are measured for the dendritic product. The mechanism of forming dendritic structure by the solvent-switching process is discussed according to Mller’s theory.