二烯
复分解
化学
聚合
无环二烯复分解
单体
反应性(心理学)
高分子化学
开环复分解聚合
聚合物
有机化学
医学
病理
天然橡胶
替代医学
作者
Ting-Wei Hsu,Samuel J. Kempel,Alyssa P. Felix Thayne,Quentin Michaudel
标识
DOI:10.1038/s41557-022-01060-6
摘要
The cis/trans geometry of olefins is known to dramatically influence the thermal and mechanical properties of polyalkenamers. Yet, polymerization methods that efficiently control this parameter are scarce. Here we report the development of a stereoretentive acyclic diene metathesis polymerization that uses the reactivity of dithiolate Ru carbenes combined with cis monomers. These Ru catalysts exhibit exquisite retention of the cis geometry and tolerate many polar functional groups, enabling the synthesis of all-cis polyesters, polycarbonates, polyethers and polysulfites. The stereoretentive acyclic diene metathesis polymerization is also characterized by low catalyst loadings and tolerance towards trans impurities in the monomer batch, which should facilitate large-scale implementation. Modulation of the reaction temperature and time leads to an erosion of stereoretention, permitting a stereocontrolled synthesis of polyalkenamers with predictable cis:trans ratios. The impact of the stereochemistry of the repeating alkenes on the thermal properties is clearly demonstrated through differential scanning calorimetry and thermogravimetric analysis.
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