Anti-UV, antibacterial, strong, and high thermal resistant polyvinyl alcohol/Uncaria gambir extract biocomposite film

Pure polyvinyl alcohol (PVA) has some weaknesses, such as low values of ultraviolet (UV)-light protection, anti-bacteria, tensile strength, and thermal resistance. We have found a new additive, i.e., Uncaria gambir (UG) extract, added to PVA to improve these properties. This study characterized PVA/UG biocomposite film prepared from the various polyphenol UG (0.05%, 0.5%, and 1%) loadings in pure PVA. The use of 1%UG resulted in almost complete UV-C absorption of about 100% without sacrificing transparency (71.8%) at 650 nm wavelength. The addition of 1%UG also increased the tensile strength by 66.8%, toughness by 93.9%, maximum decomposition temperature by 9.5%, and antibacterial properties compared to pure PVA. These findings indicate that UG could be a potential filler for PVA-based biocomposite films requiring good UV light protection, antibacterial, tensile, and thermal properties.