Eco-friendly food packaging: gallic acid as a cross-linking agent in PBAT/cellulose composite films

In the current study, a novel experimental approach was used to fabricate a biobased packaging film made of poly(butylene adipate-co-terephthalate) (PBAT) blended with cellulose (CL) and gallic acid (GA). By adding 1 wt%, 2 wt%, 3 wt%, and 5 wt% of GA to PBAT and cellulose in a 70/30 (w/w) ratio, PBAT composites have been produced using the solution casting method, with GA working as a crosslinking agent. With the use of attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis/differential scanning calorimeter (TGA/DSC) analysis, the physicochemical properties of the PBAT film reinforced with CL and PBAT-CL/GA composite film were studied. Results depicted that increasing the level of GA enhanced the mechanical properties, resistance to oxygen and water vapor permeability, hydrophobicity, and antibacterial activity of the resulting films. The PBAT/CL film prepared with 5 wt% GA had higher tensile strength (33.1 MPa) in comparison to neat PBAT film (21.9 MPa). The addition of CL and GA significantly reduced the water contact angle values of the PBAT film. In addition, the PBAT composite films exhibited strong antibacterial activity, suggesting their potential application in food packaging. Food quality analysis revealed that PBAT-CL/GA film extends the shelf life of strawberries compared to the commercial low-density polyethylene film. Therefore, the use of these composite materials prolongs the freshness of perishable fruits. Current research has revealed that the PBAT-based composite film is an excellent material for food packaging.