Carbon nanotubes induced microstructure and mechanical properties changes in cocontinuous poly( L-lactide)/ethylene-co-vinyl acetate blends

Toughening of poly( L-lactide) (PLLA) by elastomer attracts much attention in recent years; however, it is usually associated with the deterioration of modulus and/or strength, resulting in limitation in many applications of the material. In this work, functionalized multiwalled carbon nanotubes (FMWCNTs) were introduced into ethylene-co-vinyl acetate toughened PLLA blends. The effects of FMWCNTs content on crystalline structure of PLLA matrix and the morphology of the blends, as well as the selective distribution of FMWCNTs in the ternary nanocomposites were investigated using differential scanning calorimetry (DSC), wide angle X-ray diffraction, scanning electron microscope, and transmission electron microscope. The results show that FMWCNTs exhibit excellent nucleation role in improving the cold crystallization behaviors of PLLA during the annealing and/or DSC heating processes. The results of mechanical property measurements demonstrate that the modulus, strength, and ductility of the blends can be further improved simultaneously through introducing FMWCNTs. Copyright (C) 2011 John Wiley & Sons, Ltd.