Effect of electron beam irradiation on the properties of polylactic acid/montmorillonite nanocomposites for food packaging applications

Abstract

ABSTRACTThis study was aimed at (1) developing new films based on polylactic acid/montmorillonite (PLA/MMT) with improved properties for applications in the food packaging industry and (2) analyzing the effect of electron‐beam (eBeam) radiation on the structural, morphological, mechanical, and barrier properties of these nanomaterials. Nanocomposites based on PLA with 1, 3, and 5 wt % of MMT were prepared in a twin‐screw extruder and then filmed by a calender. The nanocomposites were exposed to eBeam doses; one set at 1 kGy dose and the other at 10 kGy dose. The effect of MMT addition and of eBeam radiation on the properties of PLA were assessed. For all composites, a homogeneous distribution and dispersion of MMT in the PLA matrix was obtained. All nanocomposites showed an increase of the mechanical and oxygen‐barrier properties compared to neat PLA. The eBeam irradiation caused an increase of the crystallinity, formation of crosslink, increase of the glass‐transition temperatures, and enhancement of the yield values in the stress–strain curves for all nanocomposites. This study demonstrated that PLA/MMT films are suitable materials for eBeam processing of prepacked food at the realistic doses that were employed in this study. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42219.