Mechanical, structural, thermal, morphological and migration properties of polylactic acid (PLA)/ostrich (Struthio Camelus) eggshell (OES) biocomposites for food packaging application

The advent of environmental awareness and the need for circular economies have led to huge efforts towards using sustainable materials. Packaging plastics are the biggest source of mismanaged waste. Biopolymers are expected to serve as alternatives, and polylactic acid (PLA) is a promising candidate. However, they still have some performance drawbacks that hinder their total domination of the plastic market. Several strategies to improve their performance include blending with fibers and fillers to produce biopolymer based composites. One such important filler is calcium carbonate (CaCO3), which is sourced from mining a sedimentary rock, a non-renewable resource. Aviculture waste valorisation of eggshells could serve as a suitable source of organic CaCO3. In this study, the biggest and calcite rich ostrich eggshells were proposed as a sustainable filler material for PLA biopolymer matrix. PLA was loaded with different weights of ostrich eggshell waste powder (OES) and subjected to characterisation tests, including mechanical, thermal, and food contact migration testing. 5wt% OES loading resulted in the optimum tensile strength. The composites had remarkably reduced water vapour permeability, and overall migration levels were far below the overall migration limit (10 mg/dm2). The results of this study primarily suggested potential for PLA/OES biocomposites application in food packaging.