The majority of post-consumer plastic waste is not recycled. Impediments to the recycling of commodity polymers include separation, impurities and degradation of the macromolecular structures, all of which can negatively affect the properties of recycled materials. An attractive alternative is to transform polymers back into monomers and purify them for repolymerization — a form of chemical recycling we term chemical recycling to monomer (CRM). Material recycled in this way exhibits no loss in properties, creating an ideal, circular polymer economy. This Review presents our vision for realizing a circular polymer economy based on CRM. We examine the energetics of polymerization and other challenges in developing practical and scalable CRM processes. We briefly review attempts to achieve CRM with commodity polymers, including through polyolefin thermolysis and nylon 6 ring-closing depolymerization, and closely examine the recent flourishing of CRM with new-to-the-world polymers. The benefits of heterocycle ring-opening polymerization are discussed in terms of synthetic control and kinetically accessible polymer-backbone functionality. Common chemical and structural characteristics of CRM-compatible ring-opening-polymerization monomers are identified, and the properties, benefits and liabilities of these recyclable polymers are discussed. We conclude with our perspective on the ideals and opportunities for the field.

消费后的塑料废料大部分不回收。商品聚合物回收的障碍包括分离，杂质和大分子结构的降解，所有这些都可能对回收材料的性能产生负面影响。一种有吸引力的替代方法是将聚合物转变为单体，然后将其纯化以进行再聚合-一种化学循环形式，我们称为化学循环成单体（CRM）。以这种方式回收的材料不会出现性能损失，从而实现了理想的圆形聚合物经济性。本评论介绍了我们基于CRM实现循环聚合物经济的愿景。在开发实用且可扩展的CRM流程时，我们研究了聚合的能量和其他挑战。我们简要回顾了使用商品聚合物实现CRM的尝试，包括通过聚烯烃的热解和尼龙6的闭环解聚，并密切关注最近使用新型聚合物的CRM的兴旺发展。杂环开环聚合的好处从合成控制和动力学可访问的聚合物骨架功能方面进行了讨论。确定了CRM相容性开环聚合单体的常见化学和结构特征，并讨论了这些可回收​​聚合物的性质，益处和责任。我们以对这一领域的理想和机会的看法作为结束。杂环开环聚合的好处在合成控制和动力学上可访问的聚合物骨架功能方面进行了讨论。确定了CRM相容性开环聚合单体的常见化学和结构特征，并讨论了这些可回收​​聚合物的性质，益处和责任。我们以对这一领域的理想和机会的看法作为结束。杂环开环聚合的好处从合成控制和动力学可访问的聚合物骨架功能方面进行了讨论。确定了CRM相容性开环聚合单体的常见化学和结构特征，并讨论了这些可回收​​聚合物的性质，益处和责任。我们以对这一领域的理想和机会的看法作为结束。