Highly tough, extensible, and bio-based films composed of cellulose and phenolic acids

The development of bioplastics with enhanced toughness, which effectively combine ductility and strength from renewable biomass resources, continues to pose a significant challenge. In this study, regenerated cellulose was combined with non-toxic and non-irritating bio-molecular phenolic acids, specifically hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, and gallic acid, to fabricate robust films. The composite film (C-HBA) formulated with 15 wt% hydroxybenzoic acid demonstrated a notable tensile elongation at break of approximately 56 % and a substantial tensile strength of approximately 123 MPa, achieving a toughness value of 47.79 MJ/m³. Characterization results obtained from infrared spectroscopy and X-ray photoelectron spectroscopy revealed that phenolic acids competed with cellulose chains for self-assembly, thereby introducing a novel hydrogen bond network that enhanced the mechanical properties of the films. These films, derived from non-toxic biomass resources, exhibit significant potential for applications in sectors such as food, pharmaceuticals, and agriculture.