Isolation of microcrystalline cellulose from wood and fabrication of polylacticacid (PLA) based green biocomposites

Abstract

An innovative microcrystalline cellulose (MCC) natural fibre powder-reinforced PLA biocomposite was investigated using the hand lay-up technique. The polymer matrix composite (PMC) samples were prepared by varying the weight percentages (wt.%) of both PLA matrix and MCC reinforcement: pure PLA/100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 wt.%, respectively. From the results obtained, MCC powder, with its impressive aspect ratio, proved to be an ideal reinforcement for the PLA, exhibiting exceptional mechanical properties. It was evident that the 80:20 wt.% biocomposite sample exhibited the maximum improvement in the tensile, flexural, notched impact, compressive strength and hardness by 28.85%, 20.00%, 91.66%, 21.53% and 35.82%, respectively compared to the pure PLA sample. Similarly, during the thermogravimetric analysis (TGA), the same 80:20 wt.% biocomposite sample showed a minimum weight loss of 20% at 400°C, among others. The morphological study using Field Emission Scanning Electron Microscopy (FE-SEM) revealed that the uniform distribution of cellulose reinforcement in the PLA matrix actively improved the mechanical properties of the biocomposites, especially theoptimal 80:20 wt.% sample. Importantly, it was evident that the optimal PLA/cellulose biocomposite sample could be a suitable and alternative sustainable, environmentally friendly and biodegradable material for semi/structural applications, replacing synthetic and traditional components.