ASTM D7409-15

Standard Test Method for Carboxyl End Group Content of Polyethylene Terephthalate (PET) Yarns

SIGNIFICANCE AND USE
5.1 This test method can be used for manufacturing quality control or manufacturing quality assurance purposes to determine the CEG concentration of PET yarns used in either geogrids or geotextiles.  
5.2 The CEG content of the PET yarns may have an influence on the properties of the geosynthetic, such as its hydrolysis resistance. The lower the value, the higher the hydrolysis resistance of the yarns.  
5.3 This test does not set the limiting (maximum) value for various engineering applications. Such a specification is a decision of the design engineer, owner, and/or regulator.
SCOPE
1.1 This test procedure is based significantly on the GRI GG7 test procedure, Carboxyl End Group Content of Polyethylene Terephthalate (PET) Yarns.  
1.2 This test method is used to determine the concentration, in mmol/Kg, of carboxyl end groups (CEG) found in poly(ethylene terephthalate) (PET) yarns by titration.  
1.3 This test is applicable to geogrid yarns that are made from PET resin.
Note 1: This test is also applicable to high strength geotextile yarns that are made from PET and are used in reinforcement applications.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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.

General Information

• Status: Historical
• Publication Date: 14-Feb-2015
• ICS: 59.080.20 - Yarns
• Technical Committee: D35 - Geosynthetics
• Drafting Committee: D35.02 - Endurance Properties

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D7409 − 15
Standard Test Method for
Carboxyl End Group Content of Polyethylene Terephthalate
1
(PET) Yarns
This standard is issued under the fixed designation D7409; 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 3.1.2 Carboxyl End Groups (CEG), n—non-reactedcarbox-
ylic acid groups of terephthalic acid located at either end of a
1.1 This test procedure is based significantly on the GRI
polymer chain.
GG7 test procedure, Carboxyl End Group Content of Polyeth-
3.1.3 colorimetric titration, n—atitrationmethodthatmoni-
ylene Terephthalate (PET) Yarns.
torsthechangeincolorofthesolutionasthetitrationproceeds.
1.2 This test method is used to determine the concentration,
A chemical indicator sensitive to pH is added to create the
in mmol/Kg, of carboxyl end groups (CEG) found in poly(eth-
color change.
ylene terephthalate) (PET) yarns by titration.
3.1.4 fibers, n—a generic term for any one of the various
1.3 This test is applicable to geogrid yarns that are made
types of material that form the basic structure of a geogrid (or
from PET resin.
geotextile), which are characterized by having a length at least
NOTE 1—This test is also applicable to high strength geotextile yarns
100 times its diameter.
that are made from PET and are used in reinforcement applications.
3.1.5 filaments, n—a continuous fiber of extremely long
1.4 The values stated in SI units are to be regarded as
length.
standard. No other units of measurement are included in this
3.1.6 potentiometric titration, n—a titration method that
standard.
monitors the change in electrochemical potential, expressed as
1.5 This standard does not purport to address all of the
mV, of the solution as the titration proceeds.
safety concerns, if any, associated with its use. It is the
3.1.7 titration, n—titration is a standard laboratory method
responsibility of the user of this standard to establish appro-
of quantitative chemical analysis which can be used to deter-
priate safety and health practices and determine the applica-
mine the concentration of a known reactant. Typically, the
bility of regulatory limitations prior to use.
reactionisaneutralizationreactionbetweenanacidandabase.
3.1.8 yarns, n—a generic term for a continuous strand of
2. Referenced Documents
fibers, filaments, or material in a form suitable for knitting,
2
2.1 ASTM Standards:
weaving, or otherwise intertwining to form a textile related
D123 Terminology Relating to Textiles
geogrid (or geotextile).
3. Terminology 4. Summary of Test Method
3.1 Definitions:
4.1 This method defines a specific procedure for the deter-
3.1.1 automatic titration, n—a titration method in which a mination of carboxyl end groups (CEG) of PETby a titrimetric
machine is used that automatically dispenses small volumes of method.
the titrant and monitors the pH or the electrochemical potential
4.2 PET yarns are dissolved in o-cresol at 80°C. The
of the solution.
solution is diluted with dichloro methane, and titrated against
KOH dissolved in methanol, by either a potentiometric or
colorimetric method. The amount of potassium hydroxide
1
This test method is under the jurisdiction of ASTM Committee D35 on
required to complete the titration with the PET solution is
Geosynthetics and is the direct responsibility of Subcommittee D35.02 on Endur-
measured and used to calculate to the concentration of CEGs.
ance Properties.
Current edition approved Feb. 15, 2015. Published April 2015. Originally
5. Significance and Use
ε1
approved in 2007. Last previous edition approved in 2007 as D7409 – 07 . DOI:
10.1520/D7409-15.
5.1 This test method can be used for manufacturing quality
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
control or manufacturing quality assurance purposes to deter-
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
mine the CEG concentration of PET yarns used in either
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. geogrids or geotextiles.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D7409 − 15
5.2 The CEG content of the PET yarns may have an is made, wash the affected area with water for at least 15 or 20
influence on the properties of the geosynthetic, such as its min, get medical treatment immediately. Keep solvent away
hydrolysis resistance. The lower the value, the higher the from sparks and flames.
hydrolysis resistance of the yarns.
8.4 Dichloro Methane—It is
...

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.
´1
Designation: D7409 − 07 D7409 − 15
Standard Test Method for
Carboxyl End Group Content of Polyethylene Terephthalate
1
(PET) Yarns
This standard is issued under the fixed designation D7409; 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
ε NOTE—The equation in Section 10.5 was added editorially in December 2008.
1. Scope
1.1 This test procedure is based significantly on the GRI GG7 test procedure, Carboxyl End Group Content of Polyethylene
Terephthalate (PET) Yarns.
1.2 This test method is used to determine the concentration, in mmol/Kg, of carboxyl end groups (CEG) found in poly(ethylene
terephthalate) (PET) yarns by titration.
1.3 This test is applicable to geogrid yarns that are made from PET resin.
NOTE 1—This test is also applicable to high strength geotextile yarns that are made from PET and are used in reinforcement applications.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D123 Terminology Relating to Textiles
3. Terminology
3.1 Definitions:
3.1.1 automatic titration, n—a titration method in which a machine is used that automatically dispenses small volumes of the
titrant and monitors the pH or the electrochemical potential of the solution.
3.1.2 Carboxyl End Groups (CEG), n—non-reacted carboxylic acid groups of terephthalic acid located at either end of a
polymer chain.
3.1.2 titration, n—titration is a standard laboratory method of quantitative chemical analysis which can be used to determine
the concentration of a known reactant. Typically, the reaction is a neutralization reaction between an acid and a base.
3.1.3 potentiometric titration, n—a titration method that monitors the change in electrochemical potential, expressed as mV, of
the solution as the titration proceeds.
3.1.3 colorimetric titration, n—a titration method that monitors the change in color of the solution as the titration proceeds. A
chemical indicator sensitive to pH is added to create the color change.
3.1.5 automatic titration, n—a titration method in which a machine is used that automatically dispenses small volumes of the
titrant and monitors the pH or the electrochemical potential of the solution.
3.1.4 fibers, n—a generic term for any one of the various types of material that form the basic structure of a geogrid (or
geotextile), which are characterized by having a length at least 100 times its diameter.
3.1.5 filaments, n—a continuous fiber of extremely long length.
1
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 Dec. 1, 2007Feb. 15, 2015. Published March 2008April 2015. Originally approved in 2007. Last previous edition approved in 2007 as D7409
ε1
– 07 . DOI: 10.1520/D7409-07E01.10.1520/D7409-15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. 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
1

---------------------- Page: 1 ----------------------
D7409 − 15
3.1.6 potentiometric titration, n—a titration method that monitors the change in electrochemical potential, expressed as mV, of
the solution as the titration proceeds.
3.1.7 titration, n—titration is a standard laboratory method of quantitative chemical analysis which can be used to determine
the concentration of a known reactant. Typically, the reaction is a neutralization reaction between an acid and a base.
3.1.8 yarns, n—a generic term for a continuous strand of fibers, filaments, or material in a form suitable for knitting, weaving,
or otherwise intertwining to form a textile related geogrid (or geotextile).
4. Summary of Test Method
4.1 This method defines a specific proce
...