Mass transport studies of different additives in polyamide and exfoliated nanocomposite polyamide films for food industry

Abstract

Abstract The development of new food packaging films through the incorporation of nanoparticles, and the effect of the nanoparticles on the process of migration of the substances used in manufacturing the new films is expected to lead to an improvement in the shelf life of food and thus, consumer safety and health. In recent years, attention has focused on nanocomposites because these compounds often exhibit unexpected hybrid properties derived from synergistic reactions between nanoparticles and the polymeric matrix. The exfoliation of nanoclays in polyamide film provides a film with better barrier properties than that obtained through the intercalation of nanoclays. Migration of chemicals from food packaging into food may produce potential adverse health effects because of exposure to toxic compounds. The present study addressed the migration of caprolactam, 5‐Chloro‐2‐(2,4‐dichlorophenoxy)phenol (triclosan) and trans,trans‐1,4‐diphenyl‐1,3‐butadiene (DPBD) from polyamide and polyamide‐nanoclays to different types of food simulants. The values for limit of detection (LOD) obtained for caprolactam, triclosan and DPBD was 0.5 mg/L, 0.02 mg/L and 0.01 mg/L, respectively. Furthermore, instrumental precision was evaluated through repeatability injections, resulting in relative standard deviations lower than 3.08%. Diffusion coefficients were calculated according to a mathematical model based on Fick's Second Law, and the results were discussed in terms of the parameters that may have the greatest effect on migration. The presence of polymer nanoparticles was found to slow down the rate of migration of substances from the matrix polymer into the food up to six times. Copyright © 2009 John Wiley & Sons, Ltd.