Fabrication and Characterizations of Zeolite β–filled Polyethylene Composite Films

A series of low‐density polyethylene (LDPE)/linear LDPE (LLDPE)/zeolite H‐β composites at different zeolite contents up to 10 wt% were mixed after melt and blown into film sheets. The resultant films were characterized by using X‐ray diffraction, scanning electron microscope and other physical property analyzers. X‐ray diffraction results reflect that either zeolite or polymer phase has maintained its regularly ordered microscopic structure without any observable deterioration. The scanning electron microscope morphological observation shows a good dispersion of zeolite in the PE matrix. Water vapour, oxygen and nitrogen transmission rates are all found to increase after introducing zeolite H‐β. However, tensile strength, elongation, tear strength and puncture resistance are observed to obviously drop with successive increment of zeolite content. Composite film clarity becomes poorer than the pristine film as reflected by the increase of the film haze after adding zeolite H‐β. Finally, the composite films were used as packaging materials for fresh strawberries. The gas composition variations in the packages during 5 days reflect that the O 2 and CO 2 contents have varied inside and they are apparently dependent on the zeolite loadings in the composite films, subsequently affecting respiration rates of fruit. Our experiments suggest that there is a compromise between zeolite content and film performances like mechanical, optical, barrier and packaging properties. Copyright © 2012 John Wiley & Sons, Ltd.