Carboxymethyl Cellulose (CMC)‐Based Biocomposite Reinforced With Orange Peel and Pistachio Shell Waste

Biocomposite films were prepared using carboxymethyl cellulose (CMC) as a matrix, reinforced with natural fillers such as pistachio shell powder (PSP) and orange‐peel powder (OPP), with citric acid (CA) serving as a crosslinking agent. The films were fabricated via solution casting and evaluated for their structural and functional properties. FTIR analysis indicated enhanced intermolecular interactions and hydrogen bonding, particularly in films containing 0.3 wt% PSP and 0.2 wt% CA, suggesting improved filler–matrix compatibility. PSP‐reinforced films exhibited enhanced hydrophobicity due to their higher lignin content, whereas OPP‐reinforced films showed increased moisture absorption owing to their carbohydrate‐rich composition. Crosslinked films demonstrated reduced water sensitivity and improved structural integrity. Biodegradation studies confirmed the eco‐friendly nature of the films, with PSP‐based samples showing slower degradation due to increased crosslinking density. These results highlight PSP as an effective reinforcement for improving the performance of CMC‐based films for sustainable packaging applications.