IDENTIFICATION OF VOLATILE COMPOUNDS RESULTING FROM THE THERMAL-OXIDATION OF POLYETHYLENE

The migration of compounds from polymer-based packaging may impart undesirable odors to foods. We, therefore, undertook a study of the volatile compounds produced during the heating of polyethylene (PE) in the presence of excess O2 at temperatures of 150-350-degrees-C and for heating times of 5-15 min. Eighty-four volatile compounds in the range of C5-C23 were identified by gas chromatography mass spectrometry. The major products were aliphatic hydrocarbons, aldehydes, ketones, and olefins. Changes in temperature and heating times affected the amount and type of compounds produced, with hexanal being found in the largest amount and 300-degrees-C resulting in the greatest quantity of volatile compounds. At 350-degrees-C, greater amounts and numbers of low-boiling and fewer high-boiling compounds were formed. Only small amounts of volatiles were produced at 150-degrees-C. Many of the compounds identified have been reported to have odor and/or toxicological significance.