Cellulose extracted from rice husk as filler for poly(lactic acid): preparation and characterization

The present manuscript has been focused on the extraction of cellulose from rice husk through a multi-step process. Three consecutive steps have been performed in order to separate impurities, hemicellulose, lignin and silica and thus to obtain pure cellulose. The crystallinity and morphology of the extracted cellulose have been investigated by using X-ray diffraction and scanning electron microscopy. Subsequently, poly(lactic acid) (PLA) bio-composites with different filler contents (namely, 5, 10, 20 and 30 wt%) have been prepared by melt-blending. The thermal and mechanical properties of the resulting bio-composites have been investigated and correlated with the observed morphologies. In spite of a broad micrometric distribution of the cellulose particle size, the mechanical properties turned out to be strongly improved as well as the oxygen permeability properties have proven to be reduced. These data have been compared with those of analogous compounds containing a commercial cellulose; the collected results have shown that similar mechanical properties have been found using both celluloses. Finally, this work has also demonstrated that an industrial waste as rice husk can be recycled for conferring enhanced final properties to PLA.