Synthesis of Narrow-Distribution, High-Molecular-Weight ROMP Polycyclopentene via Suppression of Acyclic Metathesis Side Reactions.
Synthesis of Narrow-Distribution, High-Molecular-Weight ROMP Polycyclopentene via Suppression of Acyclic Metathesis Side Reactions.
复制标题
通过抑制无环复分解副反应合成窄分布、高分子量 ROMP 聚环戊烯。
DOI：
10.1021/acsmacrolett.6b00969
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发表时间：
2017
影响因子：
7.015
通讯作者：
R. Register
中科院分区：
文献类型：
--
作者：
W. Mulhearn;R. Register
为了抑制活性金属-碳烯链端与无环烯烃在反应介质中的无环复分解反应速率，研究了窄分布ROMP多环戊烯的制备方法。特别是，我们研究了链间复分解，它产生具有“乱”链长度的线性聚合物，我们展示了通过链内背咬形成环状聚合物，并量化了它们在反应产物中的含量。通过控制这些副反应的相对增殖速率，我们制备了低分散的ROMP多环戊烯，其分子量比以前报道的要高得多。用动力学模型定量描述了聚合动力学，该模型考虑了添加的三甲基膦与活性链端的可逆结合。
Methods for the preparation of narrow-distribution ROMP polycyclopentene are developed to suppress the rate of acyclic metathesis: reaction between the active metal-carbene chain end and an acyclic olefin in the reaction medium. In particular, we investigate interchain metathesis, which generates linear polymers with "scrambled" chain lengths, and we demonstrate the formation of ring polymers by intrachain backbiting and quantify their content in the reaction product. By controlling the relative rates of propagation versus these side reactions, we prepare ROMP polycyclopentene with low dispersity to substantially higher molecular weights than have been reported previously. Polymerization kinetics are quantitatively described by a kinetic model, which accounts for the reversible binding of added trimethylphosphine to the active chain end.