Robust, sustainable, and degradable wood-vitrimer composites enabled by a cellulose-based dynamic imine polymer

Traditional wood-plastic composites (WPCs) usually employed fossil-based non-degradable plastics as the polymer matrix, making WPCs poor in sustainability and degradability. Herein, a new kind of sustainable and degradable WPCs, wood-vitrimer composites (WVCs, i.e., WPs/Cel-DIP composite), was developed by integrating wood powders (WPs) into a cellulose-based dynamic imine polymer (Cel-DIP) matrix via heat-pressing formation technique. The resulting WVCs exhibited ultrahigh tensile strength (56.1 MPa), flexural strength (94.9 MPa), Young's modulus (2.5 GPa), and flexural modulus (10.3 GPa). The WVCs possessed extremely high thermostability with the glass-transition temperature (Tg) of 230–250 °C and thermal degradation temperature (Td) of ˃ 300 °C. The WVCs also exhibited low water absorption ratio (as low as 2 wt%) and excellent water resistance. Moreover, such WVCs could be chemically degraded by depolymerized the dynamic imine crosslinking networks of Cel-DIP via acid-catalyzed hydrolysis. Such WVCs represent a kind of novel, sustainable, and environmentally friendly biomass-based composites.