A medium density polyethylene with peak melting point of about 125 deg C and near 61percent crystallinity has been proposed as a reference material for the Oxidative Induction Time by Differential Scanning Calorimetry[1]. The material was stabilized by a high molecular weight hindered phenol antioxidant tetrakis-[methylene 3-(3',5'-di-t-butyl-4'hydroxyphenyl) propionate] methane, (designated as AO-1) and a phosphite synergist. Although Blaine et.al. has characterized the material over several years with a multitude of standard methods, their aim was primarily to establish homogeneity and lab to lab reproducibility. Due to the wide spread use of very similar materials in medical packaging, where long term shelf life storage integrity needs to be assured, and the values in understanding fundamental polymer stability, we have undertaken a study of the material over very diverse conditions, going far beyond the experimental parameters of the original reference[1].
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