Polyvinyl alcohol/carboxymethyl cellulose/boric acid bioblend nano-composite films: Synthesis, radiation modification and optical evaluation for UV-protection properties

This scientific study develops and tests eco-friendly biodegradable films for food packaging, using Polyvinyl Alcohol/carboxymethyl cellulose/Citric acid/Glycerol/Boric acid Poly(PVA/CMC/CA/Glyc/BA) films. The blend films of Poly(PVA/CMC/CA/Glyc/BA) obtained by casting method. To enhance the films’ strength, water resistance, and ability to have UV shielding, Boric Acid nano particles (BANPs) was incorporated and modify the films by irradiation with gamma rays at a dose of 10 kGy where the water resistance was highly improved and the tensile strength was strongly improved at concentration of 7% BANPs. The structural characterization has been performed by means of infrared spectroscopy (FTIR), Swelling behavior, mechanical tests and Edex. The optical characterization of the prepared films demonstrated that the incorporation of BANPs significantly improved their transparency while retaining the potential to block harmful ultraviolet (UV) radiation. Transparency rose from 22.9% in the Poly(PVA/CMC/CA/Glyc) blank film to 77.9% at 1% BANPs, then gradually declined with further increases in BANPs, reaching 42.2% at 10% BA. Conversely, UVB blocking efficiency decreased from 92.36% (blabk) to 84.43% at 10% BA, while UVA blocking declined from 87.5% to 73.5%. All films exhibited excellent photostability after exposure to UV irradiation (λ = 365 nm) for up to 1 hour. These results confirm the suitability of the developed films for transparent, UV-protective packaging applications. Moreover, this work supports sustainable packaging strategies by repurposing a locally sourced plant material, contributing to environmentally friendly food preservation solutions.