High-performance, starch-derived bioplastics via synergistic acylhydrazone and hydrogen-bonding networks

Starch-based materials present a sustainable alternative to fossil-derived plastics but historically suffer from unsatisfactory mechanical performance, inadequate water resistance, and poor thermal stability. Here, we report a robust starch-based bioplastics (DASD) constructed through dynamic acylhydrazone chemistry reinforced by a synergistic hydrogen-bonding network. By crosslinking dialdehyde starch with rigid isophthalic dihydrazide and flexible sebacic dihydrazide, we tailored the network to achieve mechanical robustness and improved resistance to moisture and heat, while retaining dynamic functionalities. The resulting DAS-D films demonstrated a tensile strength of 66.86 MPa, a glass transition temperature above 110 °C, and marked water resistance with a water contact angle of up to 92° and a water uptake ratio as low as 2.3-3.0%. Notably, the optical and mechanical properties of DAS-D were readily tunable by varying the incorporation ratio of DAS to dihydrazide and the heat-pressing temperature. Owing to the dynamic reversibility of the acylhydrazone bonds, DAS-D further showed self-healing capability, recyclability, and degradability. This study establishes a practical route to high-performance, starch-derived bioplastics that effectively balance durability with circularity.