390 Int. J. Microstructure and Materials Properties, Vol. 7, No. 5, 2012 Copyright © 2012 Inderscience Enterprises Ltd. Influence of loading rates on morpholgy and mechanical properties of PLA/clay nanocomposites Mustapha Kaci* and Lynda Zaidi Laboratory of Organic Materials, Department of Engineering Processes, Faculty of Technology, University Abderrahmane Mira, Route de Targa-Ouzemmour, Bejaia 06000, Algeria Fax: +21334215105 E-mail: kacimu@yahoo.fr E-mail: sinda_77@yahoo.fr *Corresponding author Stéphane Bruzaud, Alain Bourmaud, Pascal Médéric and Yves Grohens Laboratoire d’Ingénierie des Matériaux de Bretagne, Université de Bretagne Sud, 56321 Lorient Cedex, France E-mail: stephane.bruzaud@univ-ubs.fr E-mail: alain.bourmaud@univ-ubs.fr E-mail: pascal.mederic@univ-brest.fr E-mail: yves.grohens@univ-ubs.fr Abstract: This paper reports some experimental results on the influence of loading rates on morphology and mechanical properties of clay nanocomposites based on polylactide (PLA). The dispersed phase was organically modified montmorillonite commercially known as Cloisite 30B and introduced at various loading rates: 1, 3 and 5 wt.%. The nanocomposites were prepared by melt intercalation in a Brabender Plasticorder mixer. Wide angle X-ray scattering showed that the clay was finely distributed in the PLA matrix and the nanocomposite morphology can be considered as intercalated/exfoliated structure, whatever the filler content. The effect of clay loadings on the mechanical properties of PLA/organoclay was investigated by nanoindentation and tensile measurements. Nanoindentation results showed a significant improvement in modulus and hardness with increase of the clay contents. This is consistent with the large increase in Young’s modulus obtained by tensile tests indicating a good correlation of mechanical properties at the macrometric and nanometric scales. Keywords: polylactide; PLA; clay; nanocomposites; melt intercalation; morphology; mechanical properties; wide angle X-ray scattering; nanoindentation.