Evaluating the potential of nanoparticles for controlling zinc stearate release from low-density polyethylene into food simulants

The present study addressed the effect of polymer nanocomposites with different loading contents of fume silica (nanospheres) and nanoclay (nanosheet) on migration of zinc stearate from packaging materials into food simulants. Specific migration levels of zinc stearate from neat low-density polyethylene (LDPE) and LDPE/nanocomposites into two food simulants stored at 40 degrees C for 10 days were determined by gas chromatography coupled with flame ionization detector. Differential scanning calorimetry (DSC) analysis showed that incorporation of nanoparticles, especially at 1 wt% loading level of nano silica, noticeably increased degree of crystallinity, which significantly reduced water vapour permeability. Nanocomposites had a lower migration of zinc stearate in comparison with neat polymer. Additionally, results of this study revealed that physical properties of the food simulant had dominant effect on migration of zinc stearate.