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.
Scope
1.1 This test method covers a procedure for the determination of the oxidative induction time (OIT) of polyolefin geosynthetics using differential scanning calorimetry.
1.2 The focus of the test is on geomembranes, but geogrids, geonets, geotextiles, and other polyolefin-related geosynthetics are also suitable for such evaluation.
1.3 The values stated in SI units are to be regarded as the standard.
NOTE 1: This standard and ISO 11357-6 2013 address the same subject matter, but differ in technical content.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
