Effects of Gamma Irradiation on Food Contact Polyethylene, Polypropylene and Polystyrene: Volatiles

Abstract

The effects of gamma irradiation on the generation of volatiles from food contact polyethylene and polypropylene were investigated using head space (HS) /GC/MS. All samples generated volatiles such as acetic acid, propionic acid, butanoic acid, 2, 2-dimethylpropionic acid, acetone, 2-butanone, 2-propanol, 2-methyl-2-propanol, hydrocarbons, etc., due to the gamma irradiation. Especially, acetic acid and acetone were formed in greatest amounts. Since, these volatiles did not exist before irradiation and their amounts increased with increasing irradiation dose, they should be degradation products from the polymer or additives by irradiation. Polypropylene generated more kinds and larger amounts of volatiles than polyethylene, which showed that polypropylene is more sensitive to irradiation. Polystyrene contained styrene and ethylbenzene as monomers before irradiation and their amounts decreased after irradiation. Polystyrene generated few degradation products during the irradiation.