Green-synthesised NH₂-MIL-101(Cr) MOF–reinforced starch bioplastic films for sustainable food packaging

Abstract

This study introduces a green, aqueous synthesis approach for NH₂-MIL-101(Cr), avoiding toxic organic solvents while preserving its high crystallinity, porosity (>1000 m2/g), and amino functionality. To develop sustainable packaging materials the synthesized MOF was incorporated into sago starch-based bioplastic films across control 0%, 1%, 3%, and 5% treatments. Nanoparticle characterizations via SEM, TEM, FTIR, XRD, and nitrogen adsorption-desorption isotherms confirmed a porous, crystalline structure (100–300 nm) with a surface area exceeding 1000 m2/g. Film characterizations using SEM, FTIR, color analysis, tensile testing, TGA, and UV-Vis spectroscopy revealed that the 3% treatment offered the best balance, with tensile strength increasing from 2.15 MPa (control) to 4.61 MPa, thermal stability improving (decomposition onset from 230 °C to 270 °C), and UV shielding enhancing (>83% transmittance at 600 nm). The 5% treatment achieved the highest tensile strength (4.84 MPa) but showed reduced elongation (45.59% vs. 125.16% in control) due to agglomeration, while 1% provided moderate improvements. These results underscore the 3% treatment as the most suitable for eco-friendly packaging, with future work recommended to optimize MOF dispersion, extend UV analysis, and evaluate biodegradability for industrial scalability.

Keywords:Bioplastic films, Green synthesis, Metal organic frameworks (MOF), Sago starch, Sustainable packaging