Effect of organoclay incorporation on thermal, physical and morphological properties of LLDPE nanocomposites for active food packaging applications

Abstract

Active films based on nanocomposites from linear low-density polyethylene (LLDPE) were prepared by melting extrusion incorporating Cloisite 30B (5 wt.%) and thymol as active compound at two different concentrations: 2 and 4 wt.%. A complete thermal, structural characterization and antioxidant capacity of all blends was carried out. Extraction procedures revealed final concentrations of thymol in the film between 40-80% of the thymol that was initially included in the films formulation. Materials with 2 and 4% of thymol presented similar antioxidant capacity. XRD results indicated a slightly lower degree of intercalation in the nanocomposites with thymol, due probably to the lower compatibility between the hydrophilic character of the clays, and the hydrophobic thymol substance. The addition of the antioxidant improved slightly the thermal stability of the polymer.