Migration of Quaternary Ammonium Cations from Exfoliated Clay/Low-Density Polyethylene Nanocomposites into Food Simulants

Abstract

Clay/polymer nanocomposites (CPNs) are polymers incorporating refined clay particles that are frequently functionalized with quaternary ammonium cations (QACs) as dispersion aids. There is interest in commercializing CPNs for food contact applications because they have improved strength and barrier properties, but there are few studies on the potential for QACs in CPNs to transfer to foods under conditions of intended use. In this study, we manufactured low-density poly(ethylene) (LDPE)-based CPNs and assessed whether QACs can migrate into several food simulants under accelerated storage conditions. QACs were found to migrate to a fatty food simulant (ethanol) at levels of ∼1.1 μg mg –1 CPN mass after 10 days at 40 °C, constituting about 4% total migration (proportion of the initial QAC content in the CPN that migrated to the simulant). QAC migration into ethanol was ∼16× higher from LDPE containing approximately the same concentration of QACs but no clay, suggesting that most QACs in the CPN are tightly bound to clay particles and are immobile. Negligible QACs were found to migrate into aqueous, alcoholic, or acidic simulants from CPNs, and the amount of migrated QACs was also found to scale with the temperature and the initial clay concentration. The migration data were compared to a theoretical diffusion model, and it was found that the diffusion constant for QACs in the CPN was several orders of magnitude slower than predicted, which we attributed to the potential for QACs to migrate as dimers or other aggregates rather than as individual ions. Nevertheless, the use of the migration model resulted in a conservative estimate of the mass transfer of QAC from the CPN test specimens.

Fire behaviour of EPDM/NBR panels with paraffin for thermal energy storage applications. Part 1: Fire behaviour

“…Organomodified clay Cloisite® 20 was obtained from BYK-Chemie GmbH (Wesel, Germany). Cloisite®20 is a bentonite or montmorillonite modified with bis(hydrogenated tallow alkyl) dimethyl ammonium chloride and according to the datasheet, it is characterized by a density of 1.8 g/cm 3 , by a particle size lower than 10 μm and by a lamellar spacing of 3.2 nm [60][61][62].…”

Hazard Analysis and Risk-Based Preventive Controls (HARPC): Current Food Safety and Quality Standards for Complementary Foods

“…For migration testing, the data should reflect severe temperature/time conditions using different food simulants and should adhere to prescribed toxicology recommendations [ 64 , 65 ].Common packaging materials utilized for infant formula and complementary food includes metal cans, plastic bags, paper, etc. The high hardness of metal cans contributes to ease of transport and storage, as well as gives anti-extrusion and moisture-proof properties.…”

Fire behaviour of EPDM/NBR panels with paraffin for thermal energy storage applications. Part 2: Analysis of the combustion residues

“…Cloisite ® 20 is a bentonite (or montmorillonite) modified with bis(hydrogenated tallow alkyl) dimethyl ammonium chloride. It has a density of 1.8 g/cm 3 , a particle size lower than 10 μm and by a lamellar spacing of 3.2 nm [39][40][41].…”