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

• Published in: Packaging technology & science Vol. 32; no. 4; pp. 175 - 183
• Main Authors: Zabihzadeh Khajavi, Maryam, Mohammadi, Reza, Ahmadi, Shervin, Farhoodi, Mehdi, Abedi, Abdol‐Samad
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 01.04.2019
• Subjects: Addition polymerization; Degree of crystallinity; Density; Flame ionization detectors; Food; Food packaging; food simulant; fume silica; Gas chromatography; Ionization; Low density polyethylenes; Migration; nanoclay; Nanocomposites; Nanoparticles; Nanospheres; Physical properties; Polyethylene; Silicon dioxide; Zinc stearate
• ISSN: 0894-3214; 1099-1522
• DOI: 10.1002/pts.2426

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°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. The LDPE nanocomposites containing 3wt% of zinc stearate with different loading contents of fume silica and nano clay were prepared via melt blending then were hot pressed into sheets in order to perform specific migration test. The results indicated that incorporation of nanoparticles into polymer matrix can reduce migration of zinc stearate into food simulants due to creation of a tortures path in polymer matrix. The results also showed that presence of nanoparticles in polymer can reduce water vapor permeability.