Biorefinery-derived amphiphilic cutin-chitosan interpolymeric networks via supramolecular self-assembly exhibiting...

There are growing environmental concerns associated with synthetic plastic coatings, particularly per- and polyfluoroalkyl-based polymers (PFAS), which are non-biodegradable and pose significant ecological risks. This study reports the development of a biodegradable and sustainable waterproof coating for paper packaging using a cutin-chitosan composite derived from leaf biomass. Cutin was extracted from leaf pulping waste liquor using a novel, solvent-free, and environmentally friendly method, yielding comparable purity and moderate recovery. A biobased cutin-chitosan composite was fabricated and evaluated as a coating for lignocellulose paper substrates. The mechanical, optical, and barrier properties of the coated paper were assessed using tensile strength testing, Fourier Transform Infrared Spectroscopy (FTIR), Thin Layer Chromatography (TLC), Mass Spectrometry (MS), Gas Chromatography - Mass Spectrometry (GC-MS), X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). Chemical analyses confirmed functional groups characteristic of cutin, while SEM imaging revealed a smooth and uniform surface morphology. The coated paper exhibited enhanced mechanical strength and significantly reduced water and oil absorption compared to uncoated and commercial packaging papers, while demonstrating comparable barrier functionality. Furthermore, the coated material showed enhanced biodegradability relative to conventional synthetic coatings. The research aligns with circular economy principles, by promoting the valorization of agricultural waste through a biorefinery approach. Overall, the findings demonstrate the potential of cutin-chitosan composites as sustainable alternatives to synthetic waterproof coatings for lignocellulosic surfaces.