Investigation of the processing and characterization of blown-film nancomposites consisting of poly(lactic acid) and organically modified montmorillonite clay.

摘要

Organically modified montmorillonite clays at a 5% loading level were introduced into a blown film grade of polylactic acid (PLA) consisting of 95% (L) and 5% (D) contents, along with a citrate ester plasticizer and processed by twin-screw extrusion using a blown film die. Processing parameters, including extruder screw speed and feeding rate, were varied to determine any influence on the film's properties. Nanocomposite films containing the 5% montmorillonite clays demonstrated improved barrier properties over the neat film along with substantial improvements in tensile properties and thermal stability. Results show a 160% improvement in water barrier, a 70% increase in Young's modulus, and a 10°C increase in thermal stability over the neat PLA film. Although substantial improvements in the neat film were demonstrated when the clays were added, no significant improvements or influences were found with respect to processing parameters. Improvement of these properties through polymer/montmorillonite nanocomposites may provide an easy way to meet the standards of many consumer products while providing a material that is environmentally friendly.