State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
Department of Chemistry, University of Colorado Boulder, Boulder, CO, 80309, USA.
Adv Mater. 2023 Feb;35(7):e2208619. doi: 10.1002/adma.202208619. Epub 2022 Dec 20.
Development of closed-loop chemically recyclable plastics (CCRPs) that can be widely used in daily life can be a fundamental solution to the global plastic waste crisis. Hence, it is of great significance to develop easy-to-recycle CCRPs that possess superior or comparable material properties to the commodity plastics. Here, a novel dual crosslinked CCRP, namely, supramolecular covalent adaptable networks (supra-CANs), is reported, which not only displays mechanical properties higher than the strong and tough commodity polycarbonate, but also exhibits excellent solvent resistance as thermosets. The supra-CANs are constructed by introducing reversible noncovalent crosslinks into the dynamic covalent polymer networks, resulting in highly stiff and strong thermosets that also exhibit thermoplastic-like ductile and tough behaviors as well as reprocessability and rehealability. In great contrast, the analogs that do not have noncovalent crosslinks (CANs) show elastomeric properties with significantly decreased mechanical strength. Importantly, the developed supra-CANs and CANs can be converted back into the initial monomers in high yields and purity at room temperature, even with additives, which enables the sustainable polymer-monomer-polymer circulation. This work provides new design principles for high-performance chemically recyclable polymers as sustainable substitutes for the conventional plastics.
开发可广泛用于日常生活的闭环可化学回收塑料（CCRP）可以成为解决全球塑料废物危机的根本方法。因此，开发易于回收的 CCRP 具有重要意义，这些 CCRP 应具有与商品塑料相当或更优的材料性能。在此，我们报道了一种新型的双交联 CCRP，即超分子共价适应性网络（supra-CANs），其不仅表现出高于强韧的商品聚碳酸酯的机械性能，而且还表现出热固性塑料的优异耐溶剂性。supra-CANs 是通过在动态共价聚合物网络中引入可逆非共价交联而构建的，从而得到高度刚性和强韧的热固性塑料，同时还表现出类似于热塑性塑料的韧性和延展性以及可再加工性和可再修复性。相比之下，没有非共价交联的类似物（CANs）则表现出弹性体性能，其机械强度显著降低。重要的是，即使添加了添加剂，所开发的 supra-CANs 和 CANs 也可以在室温下以高产率和高纯度转化回初始单体，从而实现可持续的聚合物-单体-聚合物循环。这项工作为高性能可化学回收聚合物提供了新的设计原则，可作为传统塑料的可持续替代品。
