Starch-Based Rehealable and Degradable Bioplastic Enabled by Dynamic Imine Chemistry

The increasingly serious environmental pollution caused by petroleum-based nondegradable plastics has evoked intense research interest in the development of sustainable and degradable bioplastics. Starch is one of the most promising biopolymers for the preparation of bioplastic. However, it is still a great challenge to develop starch bioplastics with high strength, low water sensitivity, and excellent water resistance. Herein, we reported a facile chemical modification method for the synthesis of a novel starch bioplastic. In this process, an easily available starch derivate, dialdehyde starch (DAS), is cross-linked using diamine based on dynamic imine chemistry to prepare DAS-based polyimine (DAS-PI). This DAS-PI exhibits excellent thermal malleability, and it can be easily thermoformed into novel starch bioplastic without using any plasticizer. The resulting starch bioplastic shows high mechanical strength (40.6 MPa), high thermal stability, and excellent water/chemical resistance, as well as heat-induced self-healing ability. Moreover, it can be easily chemically degraded and recycled. This work provides a novel method of producing high-performance starch bioplastics without using plasticizers.