Cellulose-based nanocomposite films reinforced with nano clay for enhanced packaging performance

The development of biobased alternatives to conventional plastic packaging is crucial in addressing growing environmental concerns about plastic pollution. Herein, we report a novel approach to enhance the performance of cellulose-based packaging films by chemically modifying microcrystalline cellulose (MCC) with octadecanoic acid (MCCC18) and reinforcing it with surface-modified nanoclay. The homogeneous grafting of octadecanoic acid onto MCC achieved a high degree of substitution (2.2), imparting intrinsic hydrophobicity to the cellulose matrix. Transparent composite films were fabricated via solvent casting by incorporating varying amounts (1, 3, or 5 wt%) of nanoclay. Remarkably, the composite with 3 wt% nanoclay exhibited an optimized balance of properties, including a 26 % reduction in oxygen transmission rate (OTR), a 48 % decrease in water vapor transmission rate (WVTR), significant improvement in tensile strength and modulus, and a contact angle exceeding 100°, all while retaining high optical transparency (∼85 %). These results demonstrate, for the first time, that the synergistic combination of long-chain fatty acid grafting and nanoclay reinforcement can simultaneously enhance barrier, mechanical, and hydrophobic properties of cellulose-based films. The MCCC18/nanoclay composites represent a promising biobased alternative for sustainable packaging applications, potentially replacing petroleum-derived plastics.