Standard Test Method for Oxidative Induction Time of Polyolefin Geosynthetics by 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 an 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 operatio...
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 is greater than 30 min at 150°C.  
1.5 The values stated in SI units are to be regarded as the standard. The values stated in parentheses are provided for information only.  
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 and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8.

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ASTM D5885-06(2012) - Standard Test Method for Oxidative Induction Time of Polyolefin Geosynthetics by High-Pressure Differential Scanning Calorimetry
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D5885 −06(Reapproved 2012)
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; 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 D4565 Test Methods for Physical and Environmental Per-
formance Properties of Insulations and Jackets for Tele-
1.1 This test method covers a procedure for the determina-
communications Wire and Cable
tion of the oxidative induction time (OIT) of polyolefin
D4703 Practice for Compression Molding Thermoplastic
geosynthetics using high pressure differential scanning calo-
Materials into Test Specimens, Plaques, or Sheets
rimetry.
E473 Terminology Relating to Thermal Analysis and Rhe-
1.2 The focus of the test is on geomembranes, but geogrids,
ology
geonets, geotextiles, and other polyolefin-related geosynthetics
E967 Test Method for Temperature Calibration of Differen-
are also suitable for such evaluation.
tial Scanning Calorimeters and Differential Thermal Ana-
lyzers
1.3 This test method measures the oxidative induction time
associatedwithagiventestspecimenataspecifiedtemperature E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
and pressure.
G88 Guide for Designing Systems for Oxygen Service
1.4 Thisisanacceleratedtestforhighlystabilizedmaterials.
It is applicable only to material whose OIT values under 3.4
3. Terminology
MPa of oxygen is greater than 30 min at 150°C.
3.1 Definitions:
1.5 The values stated in SI units are to be regarded as the
3.1.1 differential scanning calorimetry (DSC), n—a tech-
standard. The values stated in parentheses are provided for
nique in which the difference in heat flow inputs into a
information only.
substance and a reference material is measured as a function of
1.6 This standard does not purport to address all of the
temperatureortime,whilethesubstanceandreferencematerial
safety concerns, if any, associated with its use. It is the
are subjected to a controlled-temperature program. (See Ter-
responsibility of the user of this standard to establish appro-
minology E473.)
priate safety and health practices and determine the applica-
3.1.2 geomembrane, n—anessentiallyimpermeablegeosyn-
bility of regulatory limitations prior to use. Specific precau-
thetic composed of one or more synthetic sheets. (See Termi-
tionary statements are given in Section 8.
nology D4439.)
2. Referenced Documents
3.1.2.1 Discussion—In this test method, essentially imper-
meable means that no measurable liquid flows through a
2.1 ASTM Standards:
geosynthetic when tested in accordance with Test Method
D3895 Test Method for Oxidative-Induction Time of Poly-
D4491.
olefins by Differential Scanning Calorimetry
D4439 Terminology for Geosynthetics
3.1.3 geosynthetic, n—a planar product manufactured from
D4491 Test Methods for Water Permeability of Geotextiles polymeric material used with soil, rock, earth, or other geo-
by Permittivity
technical engineering-related material as an integral part of a
man-made project, structure, or system. (See Terminology
D4439.)
This test method is under the jurisdiction of ASTM Committee D35 on
3.1.4 high-pressure differential scanning calorimetry
Geosynthetics and is the direct responsibility of Subcommittee D35.02 on Endur-
ance Properties.
(HPDSC) , n—differential scanning calorimetry in which the
Current edition approved July 1, 2012. Published July 2012. Originally approved
substance and reference material are exposed to a controlled
in 1995. Last previous edition approved in 2006 as D5885 – 06. DOI: 10.1520/
superambient atmosphere.
D5885-06R12.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3.1.5 index test, n—a test procedure that may be used to
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
establish an order for a set of specimens with respect to the
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. property of interest.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5885−06 (2012)
3.1.6 oxidative induction time (OIT), n— the elapsed time tion of additive packages used to stabilize the test materials.
between first exposure to an oxidizing gas and the onset to The second is the potential for the influence of chemical
oxidation of a material under isothermal conditions. mechanisms which are not significant at end-use operation
3.1.6.1 Discussion—Oxidative induction time is an index conditions.
test parameter dependent upon a wide range of experimental 5.5.2 This test method uses high oxygen pressure to accel-
conditions including temperature, pressure of oxygen, purge erate the test period while making use of lower test tempera-
gas flow rate, and the presence or absence of catalysts. tures to protect additive packages.
5.6 The results from this test method may or may not
4. Summary of Test Method
correlate with those obtained by other OIT measurements such
4.1 The specimen to be tested and the corresponding refer-
as Test Method D3895 or Test Methods D4565.
ence material are heated from room temperature at a constant
rate in a non-purging, high-pressure oxygen environment at a
6. Apparatus
defined pressure. When the specified temperature has been
6.1 Differential Scanning Calorimeter— Thermal analysis
reached, the specimen is then held at that temperature until the
equipment capable of heating rates up to 20 6 1°C/min and of
oxidative reaction is displayed on the thermal curve. The OIT
automatically recording the differential heat flow between the
is the time interval from the start of the temperature program
testsampleandareferencesampleisnecessary.Theequipment
test to the onset of the oxidative reaction.
must be capable of measuring sample temperature to 61°C
4.2 Inthisprocedure,anelevatedpressureofoxygenisused
while maintaining a set temperature to 60.5°C.
to accelerate the reaction and to reduce analysis time.
NOTE 1—Modern computer-based instrumentation equipped with “iso-
4.3 Unless otherwise specified, the temperature used in this
track” modes provide adequate specimen temperature control.
test method shall be 150°C, and the chamber pressure is to be
6.2 Data Presentation Device—A printer, plotter, recorder,
maintained at 3.4 MPa (500 psi) using a constant volume test
or other recording output device capable of displaying heat
condition.
flow on the Y-axis versus time on the X-axis as output signals
from differential scanning calorimeters in 6.1.
5. Significance and Use
6.3 High-Pressure DSC Cell—Aunitcapableofmaintaining
5.1 The oxidative induction time is a characteristic of a
pressure up to 3.4 MPa (500 psig). The system shall be
compounded polyolefin product that is dependent not only on
equipped with a pressure gage to monitor the internal pressure
the type and amount of additives present, but also on the type
of the cell to permit manual release of pressure to maintain
of resin. In well-behaved systems, this test method can be used
desired level.
as a quality control measure to monitor the stabilization in
geosynthetics as received from a supplier.
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
5.2 When this test method is used to compare different
atmosphere pressure—that is, they are “gage” pressures.
geomembrane formulations containing different antioxidant
6.4 High-Pressure Oxygen Cylinder Regulator—A pressure
packages, then those results shall be considered valid only at
regulator capable of regulating a pressure up to 5.5 MPa (800
the temperature of test.
psi). The outlet of the cylinder is to be linked to the high-
5.3 This test method is intended as an geosynthetic test. Use
pressure cell using a clean stainless steel tube.
of the OIT value to estimate the lifetime of the geomembrane
6.5 Analytical Balance, 0.1-mg sensitivity.
fromwhichthetestspecimenistakenisnotaddressednorshall
it be used for this purpose.
6.6 Specimen Holders, degreased aluminum pans, 6.0 to
5.3.1 The OIT measurement is an accelerated thermal aging
7.0-mm diameter.
test and, as such, interpretation of resulting data may be
6.7 Core Hole Borer, cork borer or arch punch producing
misleading if done by an inexperienced operator. Caution
6.3-mm (0.25-in.) disks.
should be exercised in data interpretation since oxidation
reaction kinetics are a function of temperature and the proper-
7. Reagents and Materials
ties of the additives contained in the geosynthetic sample. For
7.1 All chemical reagents used in this test method shall be
example, OIT values are often used to select optimum resin
analytical grade unless otherwise specified.
formulations. Certain antioxidants, however, may generate
7.2 Hexane or Acetone, for cleaning specimen pans and
poor OIT results even though they may be adequate at their
stainless steel tubing, see 8.2 and 8.3.
intended use temperature and vice versa.
7.3 Indium (99.999 % Purity) , for calibration purposes, see
5.4 This test method can be used for other purposes such as
9.1.
manufacturing control and research and development.
7.4 Oxygen, purity >99.5 % for the test atmosphere.
5.5 Oxidation induction time is strongly dependent upon
test temperature and the partial pressure of oxygen. The higher
8. Precautions
the test temperature or the oxygen partial pressure, or both, the
shorter the oxidation induction time. 8.1 Oxygen is a strong oxidizer that vigorously accele
...

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