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

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 (C 2 H 4 ), oxygen (O 2 ), carbon dioxide (CO 2 ), and water vapor. It was found that the C 2 H 4 permeability of the films was improved because of an enhanced adsorption of C 2 H 4 by the incorporated zeolite (0–10 wt%). The preconcentrated layer (zeolite/SEBS) leads to a higher C 2 H 4 concentration gradient across the film. Moreover, the high dispersion of zeolite increased the C 2 H 4 permeation. When compared with O 2 and CO 2 , the composite films were more selective to C 2 H 4 . However, the C 2 H 4 permeation decreased in the presence of O 2 because of a competitive adsorption. In addition, the films possessed appreciate tensile properties for packaging application. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers