Synthesis and solution properties of well‐defined comb‐on‐comb graft polymers
Synthesis and solution properties of well‐defined comb‐on‐comb graft polymers
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DOI：
10.1002/pola.22872
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发表时间：
2008-08
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影响因子：
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通讯作者：
Wei Sun;Fengping Yu;Junpo He;Chaofu Zhang;Yuliang Yang
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文献类型：
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作者：
Wei Sun;Fengping Yu;Junpo He;Chaofu Zhang;Yuliang Yang
通过级联“接枝”方法制备了苯乙烯、异戊二烯和α-甲基苯乙烯的梳状共聚物。聚合物主链通过氮氧自由基聚合制备，而支链通过阴离子聚合制备。“接枝到”方法采用大分子阴离子（如聚苯乙烯基锂、聚异戊二烯基锂或聚（α-甲基苯乙烯基）锂）与前体主链上的苄基氯或环氧环的偶联化学。因此，一系列的阿坝-，ABB-和ABC-型梳梳共聚物的制备和其特征在于，通过凝胶渗透色谱仪配备了多角度激光光散射检测器和粘度计。不寻常的“U形”的回转半径，Rg，对分子量的依赖性观察到梳梳产品，这是由于延迟洗脱的密集接枝共聚物从GPC柱。结果还表明，梳-梳共聚物的形态从硬球到圆柱棒，这取决于主链与支链的长度比。© 2008 Wiley Periodicals，Inc.聚合物科学杂志A部分：聚合物化学46：5518-5527，2008
Well-defined comb-on-comb copolymers of styrene, isoprene, and α-methyl-styrene are prepared through cascade “grafting-onto” methods. The polymer main chain is prepared by nitroxide-mediated radical polymerization while the branches are prepared by anionic polymerization. The “grafting-onto” approach employs the coupling chemistry of macromolecular anions, such as polystyryllithium, polyisoprenyllithium, or poly(α-methylstyryl)lithium, toward either benzyl chloride or epoxy ring on precursor backbones. Thus a series of ABA-, ABB-, and ABC-type comb-on-comb copolymers are prepared and characterized by gel permeation chromatography equipped with a multi-angle laser light scattering detector and a viscometer. Unusual “U-shaped” dependences of radius of gyration, Rg, on molecular weight are observed for comb-on-comb products, which are attributable to delayed elution of the densely grafted copolymers from GPC columns. The result also shows that the comb-on-comb copolymers exhibit morphologies from hard sphere to cylindrical rod, depending on the length ratio of the main chain to the branches. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5518–5527, 2008