Sustainable and versatile bioplastics toward large-scale industrialization

The widespread use of petrochemical plastic films and their detrimental environmental impacts have necessitated extensive research into green and sustainable alternative materials. Among them, cellulose, starch, and their derivatives stand out for their abundant availability, biodegradability, and renewability. However, current cellulose- and starch-based film materials usually suffer from inferior comprehensive performance and inefficient production processes, failing to replace petrochemical plastic films at the level of industrialization. Herein, we developed a sustainable and versatile bioplastic film composed of carboxymethyl cellulose and modified starch by electrostatic adsorption and multiple chemical cross-linking. Inspired by traditional paper coating techniques, we have crafted an effective film-forming process and elucidated intermolecular interactions to enable large-scale production of bioplastic film. The resultant bioplastic film exhibits superior comprehensive performance to commercial plastic films in terms of tensile strength (67.4 MPa), transparency (93.05 % at 550 nm), water vapor and oxygen barrier properties (0.77 g·μm/(m 2 ·day·kPa) and 0.86 cm 3 ·μm/(m 2 ·day·kPa), respectively). Furthermore, the bioplastic film also exhibits excellent flame retardancy (LOI = 35.9 %) and antibacterial properties, while demonstrating desirable recyclability and biodegradability. Thus, from molecular interactions to large-scale industrialization, our study paves the way for developing sustainable bioplastic films with balanced overall properties, which would be a promising alternative to petrochemical plastic films.