Biodegradable Polymer Films Reinforced With Short Fibers for Sustainable UV Protection in Food Packaging Applications

ABSTRACT Short‐fiber‐reinforced biodegradable polymer films offer a promising pathway toward sustainable materials combining mechanical robustness with added functionality. Here, we present agar‐based composite films reinforced with biodegradable short electrospun poly(methyl methacrylate‐co‐methacrylic acid) fibers, examining the effects of fiber loading on mechanical, optical, and thermal performance. Short fibers were produced via a scalable electrospinning process and incorporated into agar films at 1, 5, and 10 wt.% via one‐step casting. All composite films maintained consistent thickness (∼90–93 µm). Relative to neat agar, composites containing 10 wt.% fibers exhibited a 67% increase in tensile strength and a 72% increase in toughness while maintaining ductility, indicating efficient stress transfer enabled by the dispersed short‐fiber architecture. Beyond mechanical reinforcement, fiber incorporation imparted pronounced UV‐shielding capability, reducing transmittance at 280 nm from 31.6% to 0.57% (>99% UV blocking) and visible‐light transmittance at 600 nm from 68.3% to 2.4%, enabling tunable optical control. Thermal analysis and FTIR spectroscopy confirmed fiber integrity and predominantly physical fiber–matrix interactions. These results demonstrate that poly(methyl methacrylate‐co‐methacrylic acid) electrospun short fibers can function as effective, fully biodegradable reinforcements, enabling scalable production of multifunctional polymer films with enhanced mechanical performance and sustainable UV‐protective functionality suitable for food packaging applications.