Gamma irradiation of polyethylene nanocomposites for food packaging applications against stored-product insect pests

Abstract

Films of high-density polyethylene (HDPE) incorporated with different nanoparticles, ZnO or Ag, were prepared to protect food products from the stored-product insect pests. The developed composites were irradiated at different radiation doses and the associated properties were investigated in terms of gel content percent, tensile mechanical properties, thermal properties, and morphology. The possible application of the irradiated products in food industry via the insect pest test was investigated. The gel content percentage of the irradiated HDPE films loaded with ZnO and Ag nanoparticles demonstrated higher values than those of unirradiated unloaded films and unirradiated loaded HDPE. The mechanical measurements indicated significant increments by loading with nanoparticles as well as by irradiation. The tensile strength raised up to about 177 and 158% by adding 2% ZnO and Ag, respectively. Conversely, the elongation percentage was decreased by increasing nanoparticle concentration and by radiation dose. Thermogravimetric analysis elaborated that the thermal stability of the nanocomposites was lesser than that of HDPE unloaded films, yet improved by irradiation. The insect pest test revealed that the adults of Sitophilus granarius could not penetrate the loaded and irradiated HDPE film. The most efficient formulation was reported for the HDPE films incorporated with 2% Ag irradiated with a dose of 75 kGy. J. VINYL ADDIT. TECHNOL., 25:E120–E129, 2019. © 2018 Society of Plastics Engineers.