Enhancing the Hydrophobicity and Elasticity of Poly(Lactic Acid)/Polyethylene Glycol/Beeswax Cast Films for Biodegradable Packaging: An FTIR Comparative Study

ABSTRACT Poly(lactic acid) (PLA) is a biodegradable plastic derived from natural, eco‐friendly, and biodegradable materials. The addition of polyethylene glycol (PEG), commonly studied as a plasticizer, serves to increase the flexibility of PLA. In this study, PEG was incorporated at 10 wt%, with beeswax (BW) added at loadings of 0.1, 0.2, 0.3, and 0.5 phr, and applied as a coating to enhance hydrophobicity. The results indicate that PEG enhances both the flexibility and UV–Vis protection of the films, while elongation improved 7‐fold to 178%. Furthermore, the addition of BW improves hydrophobicity. To investigate the dispersion details, FTIR spectroscopy was employed in both ATR and transmission modes. These results were correlated with morphological observations from SEM. It revealed that PEG was primarily located at the bottom of the film. This distribution was consistent with the FTIR spectral data, which also indicated a predominant concentration of PEG at the film's bottom layer. The BW blended sample shows an increasing crystallinity, while the XRD represented %X c from 9% to 37%. Summarily, the PLA/PEG with coating BW resulted in it becoming hydrophobicity from 69° to 91°, which is beneficial for biodegradable packaging applications.