A Proposed Reference Material for Oxidative Induction Time by Differential Scanning Calorimetry

Abstract

A polyethylene film sample, inhibited with a hindered phenol antioxidant, is proposed as a Standard Reference Material for oxidative induction time (OIT) testing. The mean OIT values, derived from nine interlaboratory studies and for a number of experimental conditions, are presented. The material is found to be statistically homogeneous, a necessary condition for a reference material. Further, the effects of temperature, oxygen pressure, and storage time on the proposed reference material are explored. As a kinetic parameter, the OIT value appears to be decreasing with time but in a well behaved and predictable manner. The use of a table and graph permit the user of the material to estimate its OIT value in the future. Because the material has been thoroughly tested in a wide variety of OIT conditions, it appears to be the best currently available candidate and is offered for consideration as an OIT Reference Material.