A Green Carbon‐Based Cellulose Formate Film Bioplastic with High Wet Strength, Excellent Heat Sealability, and Recyclability Fabricated Under Ambient Conditions

Cellulose-based bioplastics have great potential to replace petroleum-based plastics due to their renewability and biodegradability. However, developing cellulose-based bioplastics still faces significant challenges due to their low water resistance and lack of heat sealability. Herein, a robust and water-resistant cellulose formate film (CFF) bioplastic is prepared via LiBr hydrate pretreatment followed by formic acid esterification under ambient conditions. This flexible CFF bioplastic exhibits higher tensile strength, and its wet tensile is 9.7 and 2.6 times higher than that of commercial cellophane and polyethylene films, respectively, and superior to most reported cellulose-based films. Furthermore, this CFF bioplastic also shows unique heat sealability due to the de-crystallization by pretreatment and esterification substitution, and the sealing strength (1953 N/m) is much higher compared to the reported cellulose bioplastics and PE film. In addition, this CFF bioplastic shows better barrier properties, excellent transparency, good printability, and antibacterial properties, which are highly desired for high-quality packaging. More importantly, compared with cellophane and polyethylene films, this CFF bioplastic with green preparation route, good biodegradability, and recyclability has a much lower environmental impact. Thus, this CFF bioplastic demonstrates great potential and feasibility as a sustainable alternative to petroleum-based plastic films for high-quality and advanced applications.