ASTM-D5885 › Standard Test Method for Oxidative-Induction Time of Polyolefins by high pressure Differential Scanning Calorimetry

This test method covers a procedure for the determination of the oxidative induction time (OIT) of polyolefin geosynthetics using high-pressure differential scanning calorimetry. 

Significance and Use

5.1 The oxidative induction time is a characteristic of a compounded polyolefin product that is dependent not only on the type and amount of additives present, but also on the type of resin. In well-behaved systems, this test method can be used as a quality control measure to monitor the stabilization in geosynthetics as received from a supplier.

5.2 When this test method is used to compare different geomembrane formulations containing different antioxidant packages, then those results shall be considered valid only at the temperature of test.

5.3 This test method is intended as a geosynthetic test. Use of the OIT value to estimate the lifetime of the geomembrane from which the test specimen is taken is not addressed, nor shall it be used for this purpose.

5.3.1 Caution should be exercised in data interpretation since oxidation reaction kinetics are a function of temperature and the properties of the additives contained in the geosynthetic sample. For example, OIT values are often used to select optimum resin formulations. Certain antioxidants, however, may generate poor OIT results even though they may be adequate at their intended use temperature and vice versa.