Abstract: This article studied the xenon aging characteristics of high density polyethylene(PE-HD) used as rotational-forming packaging cases by attenuated total reflection infrared spectroscopy(ATR-FTIR). The changes in carbonyl groups, hydroxyl groups, branching degree, chain scission degree, and unsaturation degree were monitored to determine the degradation behavior. The spectra were analyzed by using Lorentz method, and the mechanism of the forming of various oxides was explored. The absorbance of unsaturation degree showed a trend of increase, while the branching degree and chain scission degree increased rapidly during the whole aging time. In early aging, the chain scission was predominant, but branching was more noticeble during later aging. The ketone was the primary oxidation product and the carboxylic acid, aldehyde, ester, and lactone products increased rapidly in the early aging progress, then slowly to a stable value.

Key words: high density polyethylene, rotational molding, packaging case, photo-oxidation aging, oxidation product