Mechanical and wear behaviour of polylactic acid matrix composites reinforced with crab-shell synthesized chitosan microparticles

Abstract

Polylactic acid (PLA) matrix composites, reinforced with chitosan microparticles were developed by the compression moulding technique. The chitosan particles were chemically synthesized from crab shell by deproteinization, demineralization and deacetylation processes. The size, functional group, structure and morphology of the chitosan micro particles were determined with the aids of dynamic light scattering particle size analyzer, Fourier Transform Infrared Spectrophotometer (FTIR), X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM) respectively. PLA and various weight fractions (2, 4, 6, 8 and 10 wt%) of chitosan particles were melt-blended by using a HAAKE PolyLab OS Rheomix batch mixer (Thermo Electron Co., USA), operated at a rotor speed of 60 rpm and a temperature of 162 °C for 10 min. The blends were then moulded into different test specimens by using carver laboratory press at a temperature of 190 °C for 12 min under an applied pressure of 0.2 kPa. The mechanical properties (tensile and impact) and wear behaviour of the developed composites were studied. The results showed that there were favourable improvements in the mechanical and wear properties of the PLA matrix composites developed. The optimum values were found at 6 wt% chitosan particles reinforcement for mechanical properties and 10 wt% for wear resistance. The scanning electron microscopic examination of the composites showed that there was a uniform particles distribution at lower weight fractions while particles clustering were noticed on the SEM images at higher weight fractions.