Design and Characterization of High-Performance Borophene Oxide-Reinforced PLA/PEG Composite Films

Borophene oxide (BO) was synthesized using a modified Hummer method and added at different ratios into a plasticized polylactic acid/polyethylene glycol (PLA/PEG) matrix via a solution-casting technique. Characterization of the produced films for potential packaging applications was carried out through thermal, mechanical, structural, morphological, and antibacterial tests. The addition of 0.5 wt % BO to the plasticized PLA film resulted in an approximately 72% increase in the tensile strength (22.6 MPa). Increasing the BO content decreased the elongation values. In TGA analysis, the Td₁₀ temperature of the PLA/PEG matrix increased from 310 °C to approximately 338 °C with the addition of a low amount of BO. The water vapor barrier of the plasticized PLA films was enhanced with 0.5-0.7 wt % BO addition but diminished at higher BO concentrations. The resulting films exhibited greater antibacterial activity against S. aureus than E. coli. Considering all film properties, the developed films were shown to be promising for biomedical and especially packaging applications, where the vapor permeation barrier and Gram-positive bacterial contamination are critical concerns due to the BO content.