ASTM D5885/D5885M-20

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D5885/D5885M − 17 D5885/D5885M − 20
Standard Test Method for
Oxidative Induction Time of Polyolefin Geosynthetics by
High-Pressure Differential Scanning Calorimetry
This standard is issued under the fixed designation D5885/D5885M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers a procedure for the determination of the oxidative induction time (OIT) of polyolefin geosynthetics
using high-pressure 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 This test method measures the oxidative induction time associated with a given test specimen at a specified temperature and
pressure.
1.4 This is an accelerated test for highly stabilized materials. It is applicable only to material whose OIT values under 3.4 MPa
of oxygen isare greater than 30 min at 150 °C.
1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used
independently of the other, and values from the two systems shall not be combined.
1.6 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8.
1.7 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.
2. Referenced Documents
2.1 ASTM Standards:
D3895 Test Method for Oxidative-Induction Time of Polyolefins by Differential Scanning Calorimetry
D4439 Terminology for Geosynthetics
D4491/D4491M Test Methods for Water Permeability of Geotextiles by Permittivity
This test method is under the jurisdiction of ASTM Committee D35 on Geosynthetics and is the direct responsibility of Subcommittee D35.02 on Endurance Properties.
Current edition approved June 1, 2017Sept. 1, 2020. Published June 2017September 2020. Originally approved in 1995. Last previous edition approved in 20152017 as
D5885/D5885M – 15.D5885/D5885M – 17. DOI: 10.1520/D5885_D5885M-17.10.1520/D5885_D5885M-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5885/D5885M − 20
D4565 Test Methods for Physical and Environmental Performance Properties of Insulations and Jackets for Telecommunications
Wire and Cable
D4703 Practice for Compression Molding Thermoplastic Materials into Test Specimens, Plaques, or Sheets
D8117 Test Method for Oxidative Induction Time of Polyolefin Geosynthetics by Differential Scanning Calorimetry
E473 Terminology Relating to Thermal Analysis and Rheology
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E967 Test Method for Temperature Calibration of Differential Scanning Calorimeters and Differential Thermal Analyzers
G88 Guide for Designing Systems for Oxygen Service
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms related to geosynthetics, refer to Terminology D4439.
3.1.2 Definitions of terms applying to thermal analysis appear in Terminology E473.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 differential scanning calorimetry (DSC), n—a technique in which the difference in heat flow inputs into a substance and a
reference material is measured as a function of temperature or time, while the substance and reference material are subjected to
a controlled-temperature program. (See Terminology E473.)
3.2.2 geomembrane, n—an essentially impermeable geosynthetic composed of one or more synthetic sheets. (See Terminology
D4439.)
3.2.2.1 Discussion—
In this test method, essentially impermeable means that no measurable liquid flows through a geosynthetic when tested in
accordance with Test Methods D4491/D4491M.
3.2.3 geosynthetic, n—a planar product manufactured from polymeric material used with soil, rock, earth, or other geotechnical
engineering-related material as an integral part of a man-made project, structure, or system. (See Terminology D4439.)
3.2.4 high-pressure differential scanning calorimetry (HPDSC), n—differential scanning calorimetry in which the substance and
reference material are exposed to a controlled superambient atmosphere.
3.2.5 index test, n—a test procedure that may be used to establish an order for a set of specimens with respect to the property of
interest.
3.2.6 oxidative induction time (OIT), n—the elapsed time between first exposure to an oxidizing gas and the onset to oxidation
of a material under isothermal conditions.
3.2.6.1 Discussion—
Oxidative induction time is an index test parameter dependent upon a wide range of experimental conditions including temperature,
pressure of oxygen, purge gas flow rate, and the presence or absence of catalysts.
4. Summary of Test Method
4.1 The specimen to be tested is heated from room temperature at a constant rate in a non-purging, high-pressure oxygen
environment at a defined pressure. When the specified temperature has been reached, the specimen is then held at that temperature
until the oxidative reaction is displayed on the thermal curve. The OIT is the time interval from the start of the temperature program
test to the onset of the oxidative reaction.
4.2 In this procedure, an elevated pressure of oxygen is used to accelerate the reaction and to reduce analysis time.
4.3 Unless otherwise specified, the temperature used in this test method shall be 150 °C, and 150 °C for polyethylene and 170 °C
for polypropylene, and the chamber pressure is to be maintained at 3.4 MPa [500 psi] using a constant volume test condition.
5. 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
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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 The OIT measurement is an accelerated thermal aging test and, as such, interpretation of resulting data may be misleading
if done by an inexperienced operator. 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.
5.4 This test method can be used for other purposes such as manufacturing control and research and development.
5.5 Oxidation induction time is strongly dependent upon test temperature and the partial pressure of oxygen. The higher the test
temperature or the oxygen partial pressure, or both, the shorter the oxidation induction time.
5.5.1 The use of high test temperature, however, may have deleterious effects. The first of these is the potential volatilization of
additive packages used to stabilize the test materials. The second is the potential for the influence of chemical mechanisms which
are not significant at end-use operation conditions.
5.5.2 This test method uses high oxygen pressure to accelerate the test period while making use of lower test temperatures to
protect additive packages.
5.6 The results from this test method may or may not correlate with those obtained by other OIT measurements such as Test
Method D3895, D8117, or Test Methods D4565.
6. Apparatus
6.1 Differential Scanning Calorimeter—Thermal analysis equipment capable of heating rates up to 20 6 1 °C ⁄min and of
automatically recording the differential heat flow between the test sample and a reference sample is necessary. The equipment must
be capable of measuring sample temperature to 61 °C while maintaining a set temperature to 60.5 °C.
NOTE 1—ModernSome computer-based instrumentation equipped with “iso-track” modes provides adequate specimen temperature control.
6.2 Data-Presentation Device—A printer, plotter, recorder, or other recording output device capable of displaying heat flow on the
y-axis versus time on the x-axis as output signals from differential scanning calorimeters in 6.1.
6.2 High-Pressure DSC Cell—A unit capable of maintaining pressure up to 3.4 MPa [500 psig]. The system shall be equipped with
a pressure gage to monitor the internal pressure of the cell to permit manual release of pressure to maintain desired level.
NOTE 2—The gage shall be accurate to 2 % at 3.4 MPa [500 psig].
NOTE 3—All pressures in this test method are indicated relative to atmosphere pressure—that pressure; that is, they are “gage” pressures.
6.3 High-Pressure Oxygen Cylinder Regulator—A pressure regulator capable of regulating a pressure up to 5.5 MPa [800 psi]. The
outlet of the cylinder is to be linked to the high-pressure cell using a clean stainless steel tube.
6.4 Analytical Balance, 0.1-mg 0.1 mg sensitivity.
6.5 Specimen Holders, degreased aluminum pans, 6.0 to 7.0-mm7.0 mm diameter.
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6.6 Core Hole Borer, cork borer or arch punch producing 6.3-mm [0.25-in.] 6.3 mm [0.25 in.] disks.
7. Reagents and Materials
7.1 All chemical reagents used in this test method shall be analytical grade unless otherwise specified.
7.2 Hexane or Acetone, for cleaning specimen pans and stainless steel tubing,tubing; see 8.2.
7.3 Indium (99.999 % Purity), for calibration purposes,purposes; see 9.110.1.
7.4 Oxygen, purity >99.5 % for the test atmosphere.
8. Precautions
8.1 Oxygen is a strong oxidizer that vigorously accelerates combustion. Keep oil and grease away from equipment using or
containing oxygen.
8.2 The stainless steel tube connecting the high-pressure cell to the oxygen cylinder must be thoroughly cleaned by hexane (or
acetone) and then dried before being connected to the cell.
8.3 The use of pressurized oxygen requires appropriate and careful handling procedures. The user of this test method shall be
familiar with the precautions described in Guide G88.
9. Sampling
9.1 The test sample is compression molded into sheet format (thickness of 250 6 15 μm) prior to analysis. Specimen disks
(6.4-mm diameter) cut from the sheet will have a weight of approximately 5 to 10 mg, depending on sample density. Select a test
sample, at least 0.1 gr (for example, ~10 mm by ~10 mm for a 1.0 mm geomembrane, or ~7 mm by ~7 mm for a 2.0 mm
geomembrane), representing the material to be analyzed. For freshly manufactured and unaged samples, select a region of the
product free of contamination, for example, marking or adhesive. For aged coupons, the selected region should also be free of
defects and located at least 12 mm away from an edge or a discontinuity, clamping areas, etc.
NOTE 4—If the sample requires homogenization prior to analysis, one of the procedures given in Appendix X1, Appendix X2, or Appendix X3 is
recommended. Poor sample uniformity will adversely affect test precision.
NOTE 5—If the sample contains a layer or layers of polymers other than polyolefins, the polyolefin may be tested separately from the entire cross section.
A recommended procedure is given in Appendix X4.
9.2 Compression mold these assembled parts Homogenization of the test sample is recommended for freshly manufactured and
unaged samples, and mandatory for aged samples. One of the procedures given in Appendix X1, Appendix X2, or Appendix
X3into a uniform plaque to a thickness of 0.25 mm [10 mil] (see can be used to homogenize the test sample after aging. After
homogenization, the test sample is compression molded into sheet format (thickness of 0.25 6 0.015 mm) prior to analysis, using
either Practice D4703). or the procedure presented in Appendix X5.
NOTE 6—The temperature at which molding takes place may be at or above the test temperature of this test method. Prolonged exposure to air at these
temperatures may induce a negative bias into OIT measurement. Molding should be performed at as low a temperature and as quickly as possible to
minimize this bias.
9.2.1 Testing 5 to 10 mg specimens cut out directly from a product (for example, sampling a geomembrane using a punch) and
tested without prior homogenization may be acceptable for monolithic, freshly manufactured, and unaged products, provided that
they represent the entire thickness of the product; that is, that there is no over-representation of the skins nor the core on the
punched specimen. In case of dispute, results obtained on specimens homogenized and compression molded to a thickness of 0.25
mm are to be considered as referee.
9.2.2 If this test is used to monitor aging of a material, the sample must be homogenized and the same preparation technique must
be used before and after aging.
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9.2.3 If the sample contains a layer or layers of polymers other than polyolefins, the polyolefin may be tested separately from the
entire cross section. A recommended procedure is given in Appendix X4.
NOTE 4—The temperature at which molding takes place may be at or above the test temperature of this test method. Prolonged exposure to air at these
temperatures may induce a negative bias into OIT measurement. Molding should be performed at as low a temperature and as quickly as possible to
minimize this bias.
9.3 Cut test specimens from the plaque using a 6.3-mm [0.25-in.] 6.3 mm [0.25 in.] bore hole cutter or punch.
9.3.1 When testing a product for specification conformance, that is, on freshly manufactured samples, single specimens may be
tested should the dispersion of the results be known to be low enough, based on historical data available for the particular
formulation tested. If such information is not available, test three specimens.
9.3.2 When evaluating the performance of a material
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