Liu Huiying, Nelson Arif Z, Ren Yi, Yang Ke, Ewoldt Randy H, Moore Jeffrey S
ACS Macro Lett. 2018 Aug 21;7(8):933-937. doi: 10.1021/acsmacrolett.8b00422. Epub 2018 Jul 27.
Reversible transformations in bulk polymers offer numerous possibilities for materials remodeling and reprocessing. While reversible systems based on dynamic covalent chemistry such as the Diels-Alder reaction and transesterification have been intensively studied to enable local bond dissociation and formation, reports regarding the reversion from bulk network polymers to monomers are rare. Herein, we report a reversibly polymerizable system based on ring-opening metathesis polymerization of cyclopentene derivatives in the bulk state. The network polymer is thermodynamically stable and mechanically robust at room temperature and readily depolymerizes at elevated temperatures to yield liquid monomers that are repolymerized to cross-linked polymers by simply cooling to room temperature. This reversible process was characterized by differential scanning calorimetry and rheological tests.
本体聚合物中的可逆转变为材料重塑和再加工提供了众多可能性。虽然基于动态共价化学的可逆体系，如狄尔斯-阿尔德反应和酯交换反应，已得到深入研究以实现局部键的断裂和形成，但关于本体网络聚合物向单体逆转的报道却很少。在此，我们报道了一种基于环戊烯衍生物本体开环易位聚合的可逆聚合体系。该网络聚合物在室温下热力学稳定且机械性能坚固，在高温下易于解聚生成液态单体，通过简单冷却至室温即可将这些单体重新聚合成交联聚合物。此可逆过程通过差示扫描量热法和流变学测试进行了表征。
