聚烯烃是日常生活中应用十分广泛的一类高分子材料。然而,聚烯烃产量的急剧增加以及材料难以降解导致了大量塑料垃圾。目前对聚烯烃的回收普遍存在能耗大、回收产品利用率低、附加值低、在回收过程中产生其他废弃物等问题。开发聚烯烃替代品的可降解材料,可以从根源上解决聚烯烃废塑料的问题。本文总结了聚烯烃的降解机理,并综述了四类可降解聚烯烃的合成方式,包括长链双官能单体缩聚、与极性单体共聚、无环二烯易位聚合以及开环聚合,总结了这些策略的优势以及面临的挑战,并对未来可降解聚烯烃的发展前景进行了展望。

Polyolefin is thermoplastic universal plastic widely used in daily life. However, the overuse of polyolefin plastic and lack of degradability has led to a large amount of plastic waste, as well as growing land and marine pollution problems. The overwhelming majority of post-consumer polyolefin plastic is not recycled. Obstacles to the recycling of waste plastic include high energy consumption, low utilization rate of recycled products, low added value, and other wastes generated in the recycling process. Polyolefins degrade very slowly in the environment, and the addition of co-degraders can also cause environmental pollution. A feasible alternative is to redesign and synthesize degradable polyolefins, which can solve waste plastic problem from the source. The synthesis of degradable polyolefins has been extensively studied over the past half century. This paper summarizes the degradation mechanism of polyolefins, including oxidative degradation and co-degradation technology. Meanwhile we review four approaches to synthesizing degradable polyolefins, which cover condensation of long-chain bifunctional monomers, copolymerization with polar monomers, acyclic diene metathesis, and ring-opening polymerization. Among them, olefin metathesis polymerization has significantly expanded the types of degradable polyolefins due to the superior tolerance of the catalysts to functional groups, such as polyester, polyacetal, polycarbonate, polyphosphoester. We discuss the forward-looking synthetic approaches offered by current research and the challenges that these degradable materials face in truly replacing polyolefin materials. Finally, we propose our perspective on the opportunities and challenges in this field.