Structure and properties of poly(lactic acid)/poly(ϵ-caprolactone) nanocomposites with kinetically induced nanoclay location
Résumé
Poly(lactic acid)/poly(ϵ-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 \textgreater 80%) of the PLA/PCL blend remained constant even in the nanocomposite containing 5% OMMT. © 2016 Wiley Periodicals, Inc.
Mots clés
Biopolymers
biopolymers and renewable polymers
Elongation at break
Lactic acid
Modified montmorillonite
morphology
Nanocomposites
Nanoparticles
Processing condition
properties and characterization
Structure and properties
Structure property relation
structure-property relations
Ternary nanocomposites
Twin screw extruders
Viscoelastic characterization
Viscoelasticity
X ray diffraction