Effects of metal nanoparticles on the physical and migration properties of low density polyethylene films

This paper reports the impact of the addition of Ag or ZnO nanoparticles on the morphological, mechanical, barrier properties and migration behavior of low-density polyethylene (LDPE) films prepared by melt extrusion. Depending on the nanoparticle concentrations, the color of the films was changed, and the light transparency decreased. The addition of nanoparticles reduced the oxygen and water vapor transmission rates, as well as the mechanical (tensile strength and percent elongation) properties, compared to pure LDPE films. ZnO nanoparticles caused a greater decrease in the tensile strength of the nanocomposite films than the Ag-containing nanoparticles. The migration tests of the majority of the films, in isooctane, ethanol and acetic acid showed that the total migration limit of 10 mg/dm2 was not exceeded. However, the migration tests of LDPE-based films containing 3 and 5% ZnO nanoparticles in 3% acetic acid, representing acidic foods, were determined as 15.93 and 23.29 mg/dm2, respectively.