Synthesis of Hyperbranched Polymers with Pendent Norbornene Functionalities via RAFT Polymerization of a Novel Asymmetrical Divinyl Monomer
Synthesis of Hyperbranched Polymers with Pendent Norbornene Functionalities via RAFT Polymerization of a Novel Asymmetrical Divinyl Monomer
复制标题
通过新型不对称二乙烯基单体的 RAFT 聚合合成具有悬垂降冰片烯官能团的超支化聚合物
DOI：
10.1021/ma9005796
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发表时间：
2009-06
期刊：
影响因子：
5.5
通讯作者：
Liu, Xiao-hui
中科院分区：
文献类型：
--
作者：
Li, Yue-sheng;Tang, Xiu-lan;Dong, Zhong-min;Liu, Xiao-hui
通过自由基聚合，合成了一种具有高反应活性甲基丙烯酸酯基团和低反应活性降冰片烯基团的新型不对称二乙烯基单体。在快速可逆加成-破碎链转移（RAFT）平衡的介导下，聚合物链自由基的浓度降低，因此直到较高的单体转化率（约90%）才发生凝胶化。由于降冰片烯基衍生的中间自由基的稳定性降低，反应温度的升高也会显著促进超支化结构的形成，这一点通过两个与不对称二乙烯基单体中乙烯基结构相似的单乙烯基单体的模型共聚体系得到证实。此外，Tri-SEC和传统的Sin-SEC以及1H NMR分析表明，在中~ -…
Hyperbranched polymers with numerous pendent norbornene functionalities have been synthesized via the radical polymerization of a novel asymmetrical divinyl monomer bearing a higher reactivity methacrylate group and a lower reactivity norbornene group. Mediated by a rapid reversible addition−fragmentation chain transfer (RAFT) equilibrium, the concentration of polymeric chain radicals is decreased, and thus the gelation did not occur until higher monomer conversions (ca. 90%). An increase in reaction temperature can also significantly promote the formation of the hyperbranched structure owing to the decreased stability of the intermediate radicals derived from the norbornene group, which was confirmed by a model copolymerization system of two single vinyl monomers with similar structures to the vinyl groups in the asymmetrical divinyl monomer. Furthermore, Tri-SEC and conventional Sin-SEC as well as 1H NMR analyses show that hyperbranched structures and higher molecular weights were formed at moderate-to-...