Cationic lignin incorporated polyvinyl alcohol films for packaging applications

Polyvinyl alcohol (PVA) films are used extensively in industry. However, their unacceptable air permeability and susceptibility to bacterial contamination are problematic for some applications. This research investigates the incorporation of kraft lignin (KL) and cationic kraft lignin (CKL) into PVA films. The results confirmed that KL enhanced UV blocking and hydrophobicity while reducing the porosity and water absorption of the PVA films. Despite improving the UV blocking, hydrophilicity, and water absorption capability of the film, the porosity and oxygen permeability of the films were reduced, and the film became antibacterial when CKL was incorporated into PVA. The results confirmed that the sustainable PVA/KL films can potentially be used for packaging applications due to their improved hydrophobicity. In contrast, PVA/CKL films can potentially be used for medical applications due to their enhanced antibacterial performance and reduced porosity.