Selective ethylene-permeable zeolite composite double-layered film for novel modified atmosphere packaging

Abstract

The composite double-layered films, for the packaging application of postharvest fruits and vegetables, were prepared by laminating low-density polyethylene (LDPE) and poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) modified with zeolite ZSM-5. The film was characterized by scanning electron microscope and differential scanning calorimeter and tested for permeation of ethylene (C2H4), oxygen (O2), carbon dioxide (CO2), and water vapor. It was found that the C2H 4 permeability of the films was improved because of an enhanced adsorption of C2H4 by the incorporated zeolite (0-10 wt%). The preconcentrated layer (zeolite/SEBS) leads to a higher C2H 4 concentration gradient across the film. Moreover, the high dispersion of zeolite increased the C2H4 permeation. When compared with O2 and CO2, the composite films were more selective to C2H4. However, the C2H4 permeation decreased in the presence of O2 because of a competitive adsorption. In addition, the films possessed appreciate tensile properties for packaging application. Copyright © 2009 Society of Plastics Engineers.