ASTM D4660-23

Standard Test Methods for Polyurethane Raw Materials: Determination of the Isomer Content of Toluenediisocyanate

SIGNIFICANCE AND USE
5.1 These test methods are suitable for research or for quality control to determine the isomer content of toluene diisocyanates.  
5.2 The isomer content of a toluene diisocyanate relates to its reactivity.
SCOPE
1.1 These test methods measure the amount of toluene-2,6-diisocyanate (2,6-TDI) isomer or toluene–2,4–diisocyanate (2,4-TDI) isomer in mixtures of the 2,4- and 2,6-isomers of toluenediisocyanate (TDI). Two different test methods are provided to give accurate results over the broad range of isomer concentrations possible.  
1.1.1 Test Method A—Applicable to TDI samples containing 5 to 95 % of 2,6-TDI isomer (5 to 95 % 2,4-TDI isomer).  
1.1.2 Test Method B—Applicable to TDI samples containing 0 to 5 % of 2,6-TDI isomer (95 to 100 % 2,4-TDI isomer).  
Note 1: These test methods are equivalent to ISO 15064.  
1.2 The values stated in SI units are to be regarded as standard.  
1.3 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.  
1.4 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.

General Information

• Status: Published
• Publication Date: 14-Mar-2023
• ICS: 83.040.30 - Auxiliary materials and additives for plastics
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.22 - Cellular Materials - Plastics and Elastomers

Standards Content (Sample)

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.
Designation: D4660 − 23
Standard Test Methods for
Polyurethane Raw Materials: Determination of the Isomer
1
Content of Toluenediisocyanate
This standard is issued under the fixed designation D4660; 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.
3
1. Scope* cialty Chemicals (Withdrawn 2009)
E456 Terminology Relating to Quality and Statistics
1.1 These test methods measure the amount of toluene-2,6-
E691 Practice for Conducting an Interlaboratory Study to
diisocyanate (2,6-TDI) isomer or toluene–2,4–diisocyanate
Determine the Precision of a Test Method
(2,4-TDI) isomer in mixtures of the 2,4- and 2,6-isomers of
E2935 Practice for Evaluating Equivalence of Two Testing
toluenediisocyanate (TDI). Two different test methods are
Processes
provided to give accurate results over the broad range of
4
2.2 ISO Standard:
isomer concentrations possible.
ISO 15064 Plastics—Aromatic Isocyanates for Use in the
1.1.1 Test Method A—Applicable to TDI samples containing
Production of Polyurethanes—Determination of the Iso-
5 to 95 % of 2,6-TDI isomer (5 to 95 % 2,4-TDI isomer).
mer Ratio in Toluenediisocyanate
1.1.2 Test Method B—Applicable to TDI samples containing
0 to 5 % of 2,6-TDI isomer (95 to 100 % 2,4-TDI isomer).
3. Terminology
NOTE 1—These test methods are equivalent to ISO 15064.
3.1 Terms used in this standard are defined in accordance
1.2 The values stated in SI units are to be regarded as
with Terminology D883, unless otherwise specified. For terms
standard.
relating to precision and bias and associated issues, the terms
1.3 This standard does not purport to address all of the
used in this standard are defined in accordance with Terminol-
safety concerns, if any, associated with its use. It is the
ogy E456.
responsibility of the user of this standard to establish appro-
3.2 Definitions of Terms Specific to This Standard:
priate safety, health, and environmental practices and deter-
3.2.1 isomer—a compound having the same molecular for-
mine the applicability of regulatory limitations prior to use.
mula (percentage composition and molecular weight) as an-
1.4 This international standard was developed in accor-
other compound but differs in chemical or physical properties.
dance with internationally recognized principles on standard-
3.2.2 isomer content—the amount of an isomer expressed as
ization established in the Decision on Principles for the
a percentage of total 2,4- and 2,6-TDI isomer amount.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
4. Summary of Test Methods
Barriers to Trade (TBT) Committee.
4.1 Both test methods are based on the quantitative mea-
surement of absorption bands arising from out-of-plane C-H
2. Referenced Documents
deformation vibrations of the aromatic ring.
2
2.1 ASTM Standards:
4.2 In Test Method A, the infrared spectrum of a cyclo-
D883 Terminology Relating to Plastics
hexane solution of the sample is recorded in the 770 to
E180 Practice for Determining the Precision of ASTM
−1 −1
840-cm region. The absorbance ratio of the 805 cm to the
Methods for Analysis and Testing of Industrial and Spe-
–1
782 cm band is measured and converted to percent 2,6-TDI,
or percent 2,4-TDI, or both, from a previously established
calibration curve.
1
These test methods are under the jurisdiction of ASTM Committee D20 on
−1
Plastics and are the direct responsibility of Subcommittee D20.22 on Cellular 4.3 In Test Method B, the absorbance of the 782-cm band
Materials - Plastics and Elastomers.
is measured from an infrared spectrum of an undiluted sample
Current edition approved March 15, 2023. Published March 2023. Originally
approved in 1959. Last previous edition approved in 2018 as D4660 - 18. DOI:
10.1520/D4660-23.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The last approved version of this historical standard is referenced on
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM www.astm.org.
4
Standards volume information, refer to the standard’s Document Summary page on Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

--------------------
...

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: D4660 − 18 D4660 − 23
Standard Test Methods for
Polyurethane Raw Materials: Determination of the Isomer
1
Content of Toluenediisocyanate
This standard is issued under the fixed designation D4660; 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 These test methods measure the amount of toluene-2,6-diisocyanate (2,6-TDI) isomer or toluene–2,4–diisocyanate (2,4-TDI)
isomer in mixtures of the 2,4- and 2,6-isomers of toluenediisocyanate (TDI). Two different test methods are provided to give
accurate results over the broad range of isomer concentrations possible.
1.1.1 Test Method A—Applicable to TDI samples containing 5 to 95 % of 2,6-TDI isomer (5 to 95 % 2,4-TDI isomer).
1.1.2 Test Method B—Applicable to TDI samples containing 0 to 5 % of 2,6-TDI isomer (95 to 100 % 2,4-TDI isomer).
NOTE 1—These test methods are equivalent to ISO 15064.
1.2 The values stated in SI units are to be regarded as standard.
1.3 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.
1.4 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
2.1 ASTM Standards:
D883 Terminology Relating to Plastics
E180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals
3
(Withdrawn 2009)
E456 Terminology Relating to Quality and Statistics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E2935 Practice for Evaluating Equivalence of Two Testing Processes
1
These test methods are under the jurisdiction of ASTM Committee D20 on Plastics and are the direct responsibility of Subcommittee D20.22 on Cellular Materials -
Plastics and Elastomers.
Current edition approved April 1, 2018March 15, 2023. Published April 2018March 2023. Originally approved in 1959. Last previous edition approved in 20122018 as
D4660 - 12.D4660 - 18. DOI: 10.1520/D4660-18.10.1520/D4660-23.
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.
3
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D4660 − 23
4
2.2 ISO Standard:
ISO 15064 Plastics—Aromatic Isocyanates for Use in the Production of Polyurethanes—Determination of the Isomer Ratio in
Toluenediisocyanate
3. Terminology
3.1 Terminology in these test methods isTerms used in this standard are defined in accordance with Terminology D883, unless
otherwise specified. For terms relating to precision and bias and associated issues, the terms used in this standard are defined in
accordance with Terminology E456.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 isomer—a compound having the same molecular formula (percentage composition and molecular weight) as another
compound but differs in chemical or physical properties.
3.2.2 isomer content—the amount of an isomer expressed as a percentage of total 2,42,4- and 2,6-TDI isomer amount.
4. Summary of Test Methods
4.1 Both test methods are based on the quantitative measurement of absorption bands arising from out-of-plane C-H deformation
vibrations of the aromatic ring.
−1
4.2 In Test Method A, the infrared spectrum of a cyclohexane solution of the sample is recorded in the 770 to 840-cm region.
−1 –1
The absorbance ratio of the 805 cm to the 782 cm band is measured and converted to percent 2,6-TDI, or percent 2,4-TDI,
or both, from a previously established calibration curve.
−1
...