ASTM D8117 Test Method for Oxidative Induction Time of Polyolefin Geosynthetics by Differential Scanning Calorimetry. This test method covers a procedure for the determination of the oxidative induction time (OIT) of polyolefin geosynthetics using differential scanning calorimetry. 

Significance and Use

5.1 The OIT is a qualitative assessment of the level (or degree) of stabilization of the material tested. This test has the potential to be used as a quality control measure to monitor the stabilization level in formulated resin as received from a supplier, prior to extrusion.

Note 2: The OIT measurement is an accelerated thermal-aging test, and as such can be misleading. Caution should be exercised in data interpretation since oxidation reaction kinetics are a function of temperature and the inherent properties of the additives contained in the sample. For example, OIT results are often used to select optimum resin formulations. Volatile antioxidants may generate poor OIT results even though they may perform adequately at the intended use temperature of the finished product.

Note 3: There is no accepted sampling procedure, nor have any definitive relationships been established for comparing OIT values on field samples to those on unused products, hence the use of such values for determining life expectancy is uncertain and subjective.