Enhanced Mechanical and Barrier Properties of PVACINKS Cross-Linked Films for Antibacterial Food Packaging

This study employed polyvinyl alcohol (PVA), cinnamaldehyde (CIN), and potassium sorbate (KS) as raw materials for the production of PVA/CIN/KS cross-linked films using the casting method. Various methods, including Fourier-transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), tensile strength (TS), elongation at break (EB), water vapor permeability (WVP), and transparency, were conducted on the cross-linked films. Additionally, we assessed the antibacterial activity of the films against Escherichia coli and Staphylococcus aureus, and examined their efficacy in preserving citrus fruits.The results demonstrated an enhancement in the mechanical properties of the films after cross-linking. Specifically, when the CIN content was 20%, the maximum TS and EB values reached 25.58 MPa and 555.98%, respectively. Cross-linking induced a denser molecular structure, significantly improving water vapor barrier properties. The WVP value decreased from 1.28 to 0.87 g<middle dot>mm/KPa<middle dot>m(2)<middle dot>h, and water resistance increased from 32.28 to 12.63%. In antibacterial tests, the cross-linked films exhibited notable inhibitory effects against both Staphylococcus aureus and Escherichia coli, with a particularly strong impact against Staphylococcus aureus. In the citrus preservation test, citrus fruits packaged with cross-linked films maintained a considerable level of commercial value even after 15 days. These findings underscore the potential application value of cross-linked films in food packaging.