可闭环回收塑料的研究进展

Research Progress of Closed-loop Recyclable Plastics

废旧塑料的回收方法主要包括机械回收和化学回收,化学回收相较机械回收,能更好地再利用废旧塑料中的物质,从而更有效地降低对环境的污染。闭环回收作为升级后更环保的技术,通过再利用循环后得到的原料,制备出与原始产品性能相同的产品,甚至可以使用添加剂生产具有高附加值或更高性能的材料。当前研究的可闭环回收塑料主要包括生物基塑料、基于动态键设计的塑料、双闭环回收塑料和易制备塑料,这些塑料在多次闭环回收之后仍能保持稳定的力学性能,并且解决了人们日常使用的塑料再利用时出现的加工率低和难降解等问题。可以通过动态键的设计实现再利用,从混合塑料废物流中选择性分离出原始单体,重新制备出与原始材料几乎相同的塑料。双闭环回收塑料更是为我们提供了一种在单体、线性聚合物、循环聚合物之间无限循环,永远不会变成废物的材料。未来还需寻找高效统一的分类技术,减少合成塑料的原料种类,开发新的可闭环回收技术,实现真正的可持续发展。

The recycling methods for waste plastics mainly include mechanical recycling and chemical recy-cling,and chemical recycling can better reuse the substances in waste plastics than mechanical recycling,thus more effectively reducing environment pollution.Closed-loop recycling,as an upgraded and more environmentally friendly technology,reuses the raw materials obtained after the recycling to prepare products with the same performance as the original product,and even uses additives to produce materials with high added value or higher performance.The closed-loop recyclable plastics currently studied mainly include bio-based plastics,plastics based on dynamic bond design,double closed-loop recyclable plastics and easily prepared plastics,which can maintain stable mechanical properties after multiple closed-loop recycling and solve the problems in reusing the plastics used by people in daily life such as low processing rate and difficult degradation.Reuse can be achieved through the design of dynamic bonds.The original monomer is selectively separated from the mixed plastic waste stream,and plastics almost identical to the original material is reproduced.Double closed-loop recyclable plastics provide us with a material that recycles infinitely among monomer,linear polymer and recycled polymer and will never become waste material.In the future,it is necessary to find efficient and unified classification technologies,reduce the types of raw materials for synthetic plastics,and develop new closed-loop recycling technologies,so as to achieve true sustainable development.