Properties of clays reinforced PLA nanocomposites by melt extrusion technique

Abstract

Nanocomposites were prepared by melt extrusion technique using single screw extruder and subsequent hot compression. In this work, poly lactic acid-clay nanocomposites were obtained using two types of clays, namely commercial montmorillonite (Cloisite 30B) and commercial bentonite. Nanocomposites were prepared at low clay composition of 0.5, 1, 3, and 5 wt.% of clays. From XRD spectra, the partially exfoliation of nanoclay layers were occurred during melting extrusion. It resulted in improvement of mechanical properties, such as Young’s modulus, tensile strength, and elongation at break. The highest tensile strength was obtained by the addition of 0.5 wt.% commercial bentonite increasing about 23.25% compared to the neat PLA. The increasing composition of clays revealed a decrease in mechanical properties due to filler-filler interaction. Furthermore, water absorption of nanocomposites up to `1 wt.% of clays better than the neat PLA. Biodegradability was enhanced in the presence of higher clay composition due to high hydrophilicity of clay, high water uptake, and high interactions. The results show that the weight loss of the neat PLA and the nanocomposite with the addition of 5 wt.% of Cloisite 30B are 4.0% and 10.8%, respectively.