PDF(Pubmed)
Abstract：
The development of degradable polymers has commanded significant attention over the past half century. Approaches have predominantly relied on ring-opening polymerization of cyclic esters (e.g., lactones, lactides) and N-carboxyanhydrides, as well as radical ring-opening polymerizations of cyclic ketene acetals. In recent years, there has been a significant effort applied to expand the family of degradable polymers accessible via olefin metathesis polymerization. Given the excellent functional group tolerance of olefin metathesis polymerization reactions generally, a broad range of conceivable degradable moieties can be incorporated into appropriate monomers and thus into polymer backbones. This approach has proven particularly versatile in synthesizing a broad spectrum of degradable polymers including poly(ester), poly(amino acid), poly(acetal), poly(carbonate), poly(phosphoester), poly(phosphoramidate), poly(enol ether), poly(azobenzene), poly(disulfide), poly(sulfonate ester), poly(silyl ether), and poly(oxazinone) among others. In this review, we will highlight the main olefin metathesis polymerization strategies that have been used to access degradable polymers, including (i) acyclic diene metathesis polymerization, (ii) entropy-driven and (iii) enthalpy-driven ring-opening metathesis polymerization, as well as (iv) cascade enyne metathesis polymerization. In addition, the livingness or control of polymerization reactions via different strategies are highlighted and compared. Potential applications, challenges and future perspectives of this new library of degradable polyolefins are discussed. It is clear from recent and accelerating developments in this field that olefin metathesis polymerization represents a powerful synthetic tool towards degradable polymers with novel structures and properties inaccessible by other polymerization approaches.
摘要：
在过去的半个世纪中,可降解聚合物的开发引起了极大的关注。方法主要依赖于环酯的开环聚合(例如，内酯,丙交酯）和N-羧酸酐，以及环状烯酮缩醛的自由基开环聚合。近年来,已经进行了大量的努力来扩展可通过烯烃易位聚合获得的可降解聚合物家族。鉴于烯烃易位聚合反应一般具有优异的官能团耐受性,可以将宽范围的可想到的可降解部分引入到合适的单体中,从而引入到聚合物主链中。这种方法已被证明在合成广谱的可降解聚合物，包括聚（酯），聚（氨基酸），聚（缩醛），聚碳酸酯，聚（磷酸酯），聚(氨基磷酸酯)，聚(烯醇醚)，聚(偶氮苯)，聚（二硫化物），聚（磺酸酯），聚(甲硅烷基醚)，和聚（恶嗪酮）等。在这次审查中,我们将重点介绍已用于获取可降解聚合物的主要烯烃易位聚合策略，包括（i）无环二烯易位聚合，（ii）熵驱动和（iii）焓驱动的开环易位聚合，以及(iv)级联烯炔易位聚合。此外,强调并比较了通过不同策略对聚合反应的活力或控制。潜在的应用,讨论了这种新型可降解聚烯烃库的挑战和未来前景。从该领域的最新和加速发展中清楚的是,烯烃易位聚合代表了一种针对可降解聚合物的强大合成工具,所述可降解聚合物具有其他聚合方法无法获得的新结构和性能。
