Characterization and performance of additive manufactured novel bio-waste polylactic acid eco-friendly composites.

Abstract

The present work focusses on developing a completely sustainable, ecological, biodegradable, and eco-friendly composite material for edible as well as health product packaging utilizing an existing production technology. Ground chitin and chitosan powder were blended with eco-friendly polylactic acid (PLA) pellets and transformed into filaments by an extrusion process; thereafter composite parts produced by 3D printing were subjected to mechanical testing, morphological examination, crystallographic examination, chemical composition analysis and thermal analysis. Composite specimens containing chitin and chitosan, respectively, were obtained with varying mass fraction. The 3D printed composite specimen containing respectively chitin and chitosan yielded reduced tensile and flexural properties; for instance, for Chitin/PLA composite with 0.5 wt% (chitin), the tensile strength and flexural strength were 6.9 MPa and 10.4 MPa respectively. The addition of chitin reinforcement to the eco-friendly composite led to increased density with a maximum value of 1.285 g/cm3 for Chitin/PLA composite at 0.5 wt% of chitin reinforcement. However, both Chitosan/PLA and Chitin/PLA composite exhibited enhanced ductility compared to neat PLA. Additionally, the micrographs of the composites revealed the presence of voids and impurity-like particle reflecting decomposed chitin and chitosan. Insights into the chemical bonding and composition were gained by analysing the Fourier transform infrared spectra; analysis of the X-ray diffraction pattern revealed the crystal size and crystallinity index with values of 7.7 nm and 62%, respectively (e.g. Chitin/PLA composite at 0.5 wt%). Finally, the thermogravimetric analysis revealed that both composite materials exhibited a thermal stability of around 257 °C. Altogether, these findings support the use of the Chitosan/PLA and Chitin/PLA composites in applications such as food product packaging.