Standard Historical Last Updated: Apr 15, 2015
ASTM D7409-07e1

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

Significance and Use

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.

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.

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.


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 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.

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Book of Standards Volume: 04.13
Developed by Subcommittee: D35.02
Pages: 3
DOI: 10.1520/D7409-07E01
ICS Code: 59.080.20