Poly(lactic acid)/Aluminum Oxide Composites Fabricated by Sol-Gel and Melt Compounding Processes

Aluminum-oxide-coated PLA pellets, particles derived from aluminum oxide sol-gel, and calcinated alpha-Al2O3 powders were used to fabricate PLA/AlOx composites. The formation of aluminum oxide was confirmed by FTIR and EDS. SEM images suggested the melt compounding system provided a fairly homogeneous dispersion of AlOx particles in the PLA matrix. XRD analysis showed PLA and PLA/AlOx composites were both amorphous. The incorporation of AlOx particles did not alter the melting temperature of PLA. However, the shape and intensity of the melting endotherms was significantly changed, suggesting bimodal melting behavior. UV-Vis transmission spectra suggested that PLA/AlOx composites may act as a better UV barrier than neat PLA.