Tough, Recyclable and Degradable Plastics with Multi-functions Based on Supramolecular Covalent Adaptive Networks

The environmental problem of "white pollution" caused by traditional non-degradable plastics is becoming increasingly serious. Thus, the development of degradable and recyclable plastics attracts lots of attention from researchers. However, the currently reported plastics have limitations in eliminating pollution in the sea and achieving the balance between ductility and strength. Herein, a recyclable, degradable and water-soluble plastic with robust toughness is prepared based on the supramolecular covalent adaptive network, which is synthesized through crosslinking copolymer and poly(vinyl alcohol) PVA chains with dynamic boronic ester/hydrogen bonds and doping lignin component via forming hydrogen bonds between polymer chains. Such plastic exhibits excellent mechanical properties, showing a toughness of up to 148 MJ m−3 due to the combination of supramolecular and covalent adaptive networks. Significantly, the water dissolution rates and mechanical properties of plastics can be tuned over a wide range by adjusting the molar masses and hydrolysis degrees of PVA and changing the water contents. In addition, the plastic displays superior functions, such as antimicrobial, anti-UV and antioxidant properties, making it potential for applications in plenty of fields. This work paves a creative path for designing recyclable and degradable plastics with high performance to reduce "white pollution".