Sustainable Polymeric Materials Recycling materials/plastics is a major challenge for our world. In article number 2308666, Yuanxin Deng, Qi Zhang and Ben L. Feringa introduce a family of reversible and dynamic chemical bonds as a molecular toolbox for the design of sustainable polymeric materials. The key principle is to replace inert chemical bonds in traditional plastics with breakable or exchangeable linkages, e.g. noncovalent and dynamic covalent bonds, to render materials with self-healing, reprocessable and recyclable abilities. Emerging building blocks, methodologies and future opportunities and challenges are summarized and outlooked.