Mechanically Strong, Hydrostable, and Biodegradable Starch–Cellulose Composite Materials for Tableware

The extensive use of nondegradable plastic tableware has brought serious environmental problems. Starch‐based materials are good alternatives to plastics, but poor mechanical properties and intrinsic hydrophilicity limit their utilizations. In order to address this issue, naturally abundant bagasse pulp fiber is used as the reinforcing agent to improve the mechanical properties of starch and polydimethylsiloxane coating (CSB35‐PDMS50) to improve their hydrophobicity and hydrostability. CSB35‐PDMS50 reaches the tensile strength of 21.2 MPa and contact angle of 121°. The enhancement of the mechanical strength can be explained by strong hydrogen bonding between starch and cellulose, as indicated by noncovalent interaction‐reduced density gradient (NCI‐RDG) analysis. CSB35‐PDMS50 retains the low water adsorption rate within 60 h, remains stable in water for 24 h without morphology change, and maintains initial hydrophobicity after continuous abrasion in sandpaper and high‐pressure water spraying due to the formation of Si─O–C bonds. The water absorption capacity of CSB35‐PDMS50 is less than 10% when used as the cap materials for Eppendorf tube for 30 days. Furthermore, CSB35‐PDMS50 demonstrates good biodegradability in the soil with 74% in 100 days. The tableware prepared from ther composites demonstrates good potentials as the competitive substitute for plastics with easy production, high strength, and biodegradability. In this paper, mechanically strong, hydrostable, and biodegradable starch–cellulose composites are prepared by using biomass waste bagasse fiber as reinforcement and PDMS as the hydrophobic coating for tableware applications. The use of double planetary mixer greatly improves the dispersion of bagasse fiber in starch and enhances the mechanical strength. The preparation process is simple and suitable for large‐scale production.