Study of the thermal oxidation of polyole‐fins. V. Volatile products in the thermal oxidation of polyethylene

Abstract

Abstract Organic volatiles formed in the thermooxidation of polyethylene at 150 and 160°C, 760 torr oxygen pressure were investigated by gas chromatographic analysis. Aldehydes and ketones having a linear chain were identified as the major components of the organic fragments investigated. Their concentration in the gas phase was found to decrease with increasing molecular weight; the main component was acetaldehyde which was present in an amount exceeding that of any other component by nearly one order of magnitude. A considerable amount of ethylene and low molecular weight alcohols was also found in the degradation atmosphere. The evolution kinetics of the volatile products has been described by S type curves very similar to those of oxygen absorption with the period of maximum slopes coinciding with maximum hydroperoxide content in the polymer. Organic compounds are estimated to constitute only a small percent of the total amount of volatiles, in accordance with previous observations, recording that water is the dominant component.