Polylactic acid/akermanite biocomposite films for food packaging applications

Abstract

This study investigated the incorporation of akermanite into a polylactic acid (PLA) matrix using the solution casting method, with akermanite ratios ranging from 0.05% to 2% w/w. To facilitate even distribution of akermanite, 5 wt% triacetin was used as a plasticizer. The resultant PLA/akermanite composite films were evaluated and compared against neat PLA and plasticized PLA films in terms of color, optical, physical, mechanical, thermal and structural properties. Fourier-transform infrared spectroscopy (FT-IR) revealed structural formations attributed to the added plasticizers and akermanite in the PLA matrix. The films containing akermanite showed reduced transparency compared to neat PLA. Differential Scanning Calorimetry (DSC) results indicated an enhancement in crystallinity with the addition of akermanite to the PLA matrix, which suggests improved thermal properties. Mechanical testing showed that the inclusion of triacetin decreased the tensile strength of the PLA films from 31.01 MPa to 29.19 MPa, while the Young's modulus increased from 1.23 GPa to 1.33 GPa. The elongation at break also improved significantly, rising from 5.60% to 8.26%. These changes indicate an overall enhancement in the ductility and stiffness of the films. Additionally, the water solubility and moisture content of the composite films decreased, whereas their water absorption increased compared to neat PLA. These results suggest that the PLA/akermanite composites, with altered physical and mechanical properties, have significant potential for use as biocomposite materials in food packaging applications, offering a sustainable alternative with enhanced performance characteristics.