Synthesis of Novel Star Polymers with Vinyl-Functionalized Hyperbranched Core via ``Arm-First'' Strategy
Synthesis of Novel Star Polymers with Vinyl-Functionalized Hyperbranched Core via ``Arm-First'' Strategy
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DOI：
10.1021/ma1014275
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发表时间：
2010-09
期刊：
影响因子：
5.5
通讯作者：
Zhong-min Dong;Xiao-hui Liu;Hewen Liu;Yue-sheng Li
中科院分区：
文献类型：
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作者：
Zhong-min Dong;Xiao-hui Liu;Hewen Liu;Yue-sheng Li
在中等到高的单体转化率下成功地制备了带有乙烯基官能化超支化核的星星聚合物（约100 g）。80%）通过修改后的“手臂优先”策略。这是通过甲基丙烯酸酯型不对称二乙烯基单体与硫代苯甲酸酯封端的聚苯乙烯作为大分子链转移剂（Macro-CTA）的可逆加成-断裂链转移聚合来实现的。无论是分子间还是分子内交联发生高水平的单体转化率。大分子CTA的分子量（MW）显著影响所得星星聚合物的结构。低分子量的Macro-CTA有利于形成具有大核和多个短臂的星星共聚物，而高分子量的Macro-CTA限于具有小核和仅几个长臂的结构。此外，CA。保留在超支化核中的70%侧基乙烯基可以使用环氧化和UV引发的硫醇烯加成反应等反应直接改性，从而产生...
Star polymers bearing vinyl-functionalized hyperbranched cores were successfully prepared at moderate-to-high monomer conversions (ca. 80%) via a modified “arm-first” strategy. This was achieved by reversible addition−fragmentation chain transfer polymerization of a methacrylate type asymmetrical divinyl monomer with thiobenzoate-capped polystyrenes as macro-chain-transfer agents (Macro-CTAs). Neither intermolecular nor intramolecular cross-linking occurred up to high levels of monomer conversion. The molecular weights (MWs) of Macro-CTAs significantly influence the structures of the resultant star polymers. A lower-MW Macro-CTA favors the formation of a star copolymer bearing big core and multiple short arms, whereas a higher-MW one is confined to the architecture bearing small core with only a few long arms. Moreover, the ca. 70% pendant vinyl groups remained in the hyperbranched core can be directly modified using reactions such as epoxidation and UV initiated thiol−ene addition reactions, resulting in...