Multifunctional epoxy-based nanocomposite coating for tinplate: Enhancing food packaging with superior mechanical, anticorrosion, and antimicrobial properties.

This study explores the performance of a novel epoxy-based nanocomposite coating for tinplate, specifically tailored for food packaging applications requiring enhanced protection and durability. The coating matrix comprises reduced graphene oxide (rGO), chitosan (CS), and tin titanate (SnTiO₃), with functionalized SnTiO₃ nanoparticles anchored onto the rGO surface and incorporated into an epoxy resin. The resulting EP/rGO/CS/TT nanocomposite significantly improves mechanical properties, including tensile strength, while providing exceptional gas and moisture transmission resistance. Chitosan enhances the coating with antimicrobial activity, reducing microbial contamination and extending the lifespan of packaged goods. Tin titanate contributes to photocatalytic and corrosion-inhibiting properties, boosting antimicrobial and anticorrosion performance. Electrochemical impedance spectroscopy revealed superior corrosion resistance, with high charge transfer resistance (2.65 × 1013 Ω·cm2) and coating resistance (2.35 × 1013 Ω·cm2) after 600 h of immersion. Mechanical tests confirmed improved robustness, making the coating suitable for flexible and durable packaging. Additionally, the nanocomposite exhibited excellent antibacterial activity, outperforming pure epoxy and individual components against Gram-positive and Gram-negative bacteria. This multifunctional nanocomposite coating integrates mechanical strength, corrosion resistance, and antimicrobial protection, offering a promising solution for safer, longer-lasting food packaging materials.