Structure and properties of poly(lactic acid)/poly(epsilon-caprolactone) nanocomposites with kinetically induced nanoclay location
Year: 2016
Journal: J. Appl. Polym. Sci.
Authors: Urquijo, J; Dagreou, S; Guerrica-Echevarria, G; Eguiazabal, JI
Poly(lactic acid)/poly(epsilon-caprolactone)/organically modified montmorillonite (PLA/PCL/OMMT) nanocomposites were melt-processed in a twin-screw extruder under high shear conditions. As a result of the processing conditions employed, the OMMT layers located in the less compatible PCL phase in all the ternary nanocomposites. The morphology of the PLA/PCL blend evolved from "sea-island" to co-continuous upon the addition of OMMT. Both the X-ray diffraction (XRD) and viscoelastic characterization suggested similar OMMT dispersion in the reference PLA binary and in the PLA/PCL ternary nanocomposites, regardless of its location in the PLA and PCL phase, respectively. The reinforcing effect of the organoclay was also similar. The addition of OMMT to the PLA/PCL blend fully compensated the loss in stiffness and oxygen barrier performance produced by PCL in PLA; the nanocomposite with 3% OMMT showed the same modulus and permeability values as those of pure PLA. Moreover, the ductile behavior (elongation at break >80%) of the PLA/PCL blend remained constant even in the nanocomposite containing 5% OMMT. (C) 2016 Wiley Periodicals, Inc.
