Poly(oxime-ester) Vitrimers with Catalyst-Free Bond Exchange
Poly(oxime-ester) Vitrimers with Catalyst-Free Bond Exchange
复制标题
具有无催化剂键交换功能的聚（肟酯）Vitrimers
DOI：
10.1021/jacs.9b06668
复制
发表时间：
2019-09-04
影响因子：
15
通讯作者：
Russell, Thomas P.
中科院分区：
文献类型：
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作者：
He, Changfei;Shi, Shaowei;Russell, Thomas P.
玻璃体是由组成玻璃体的可交换键决定的，在高于阈值温度的凝聚相中发生缔合键交换反应的网络聚合物。对于玻璃体、依赖于低亲核键交换伙伴(例如，羟基官能化的烷烃)或低亲电性可交换键的化学物质，催化剂需要降低阈值温度，这是不可取的，因为催化剂的淋洗或失活会随着时间的推移减弱其影响，并可能影响重复使用。在这里，我们展示了如何在依赖于催化剂的聚酯玻璃体中进行无催化剂的键交换反应，而不是传统的酯键，而是使用肟酸酯。采用硫醇-烯点击化学方法合成了具有较高延伸性和延展性的POE玻璃化聚合物。POE玻璃化聚合物易于回收，其初始机械性能几乎不会下降，这表明可持续塑料有令人兴奋的机会。
Vitrimers are network polymers that undergo associative bond exchange reactions in the condensed phase above a threshold temperature, dictated by the exchangeable bonds comprising the vitrimer. For vitrimers, chemistries reliant on poorly nudeophilic bond exchange partners (e.g., hydroxy-functionalized alkanes) or poorly electrophilic exchangeable bonds, catalysts are required to lower the threshold temperature, which is undesirable in that catalyst leaching or deactivation diminishes its influence over time and may compromise reuse. Here we show how to access catalyst-free bond exchange reactions in catalyst-dependent polyester vitrimers by obviating conventional ester bonds in favor of oxime-esters. Poly(oxime-ester) (POE) vitrimers are synthesized using thiol-ene click chemistry, affording high stretchability and malleability. POE vitrimers are readily recycled with little degradation of their initial mechanical properties, suggesting exciting opportunities for sustainable plastics.