ASTM D7252-22

Standard Test Method for Polyurethane Raw Materials: Determination of Monomer and Isomers in Isocyanates

SIGNIFICANCE AND USE
5.1 This test method is used for research or for quality control to characterize isocyanates used in polyurethane products.
SCOPE
1.1 This test method determines the percent by weight of monomeric isomers and total monomer in crude or modified isocyanates. The test method is applicable to methylene di(phenylisocyanate) (MDI) and polymeric (methylene phenylisocyanate) (PMDI). (See Note 1.)  
1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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.
Note 1: There is no known ISO equivalent to this standard.  
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: 30-Jun-2022
• ICS: 19.020 - Test conditions and procedures in general
• ICS: 83.040.01 - Raw materials for rubber and plastics in general
• ICS: 83.100 - Cellular materials
• 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: D7252 − 22
Standard Test Method for
Polyurethane Raw Materials: Determination of Monomer and
1
Isomers in Isocyanates
This standard is issued under the fixed designation D7252; 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. Terminology
1.1 This test method determines the percent by weight of 3.1 For definitions of terms used in these test methods see
monomeric isomers and total monomer in crude or modified Terminology D883, unless otherwise specified. For terms
isocyanates.Thetestmethodisapplicabletomethylenedi(phe- relating to precision and bias and associated issues, the terms
nylisocyanate)(MDI)andpolymeric(methylenephenylisocya- used in this standard are defined in accordance with Terminol-
nate) (PMDI). (See Note 1.) ogy E456.
1.2 Units—The values stated in SI units are to be regarded
4. Summary of Test Method
as standard. No other units of measurement are included in this
4.1 The sample is reacted (derivatized) with methanol to
standard.
form a mixture of methyl urethanes. The urethanes mixture is
1.3 This standard does not purport to address all of the
then separated by normal phase high performance liquid
safety concerns, if any, associated with its use. It is the
chromatography (HPLC). The separated, derivatized isomers
responsibility of the user of this standard to establish appro-
are quantified through the use of an internal standard.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
5. Significance and Use
NOTE 1—There is no known ISO equivalent to this standard.
5.1 This test method is used for research or for quality
1.4 This international standard was developed in accor-
control to characterize isocyanates used in polyurethane prod-
dance with internationally recognized principles on standard-
ucts.
ization established in the Decision on Principles for the
6. Apparatus
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
6.1 High Performance Liquid Chromatograph, consisting
Barriers to Trade (TBT) Committee.
of:
6.1.1 Binary (or greater) solvent pump, capable of main-
2. Referenced Documents
taining a pulse-free flow rate of 1-3 milliliters per minute
2
2.1 ASTM Standards:
6.1.2 Sample injector, automatic or manual, capable of
D883 Terminology Relating to Plastics
reproducibly injecting a 2 microliter volume
E456 Terminology Relating to Quality and Statistics
6.1.3 Column heater, capable of maintaining a temperature
E682 Practice for Liquid Chromatography Terms and Rela-
of 30 6 0.2°C
tionships
6.1.4 UV detector, capable of measurements at 235 nm.
E691 Practice for Conducting an Interlaboratory Study to
6.1.5 Chart recorder or Data system, capable of peak area
Determine the Precision of a Test Method
integration.
E2935 Practice for Evaluating Equivalence of Two Testing
6.2 HPLC analytical column, 250 mm by 4.6 mm by 5 µm
Processes
cyano stationary phase.
1 NOTE 2—Other chromatographic columns are used provided it is
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
ascertained that similar chromatographic performance is obtained.
and is the direct responsibility of Subcommittee D20.22 on Cellular Materials -
Plastics and Elastomers.
6.3 Magnetic Stirring Hotplate.
Current edition approved July 1, 2022. Published July 2022. Originally approved
in 2006. Last previous edition approved in 2017 as D7252 - 17. DOI:10.1520/
7. Reagents and Materials
D7252-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
7.1 Purity of Reagents—Reagent-grade chemicals are to be
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
used in all tests. Unless otherwise indicated, it is intended that
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. all reagents conform to the specifications of the Committee on
*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

---------------------- Page: 1 ----------------------
D7252 − 22
Analytical Reagents of theAmerican Chemical Society, where column to avoid interference with subsequent analyses. A
such specifications are available. Other grades are used, solvent program such as the one below is used for ana
...

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: D7252 − 17 D7252 − 22
Standard Test Method for
Polyurethane Raw Materials: Determination of Monomer and
1
Isomers in Isocyanates
This standard is issued under the fixed designation D7252; 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 Scope*
1.1 This test method determines the percent by weight of monomeric isomers and total monomer in crude or modified isocyanates.
The test method is applicable to methylene di(phenylisocyanate) (MDI) and polymeric (methylene phenylisocyanate) (PMDI). (See
Note 1.)
1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
NOTE 1—There is no known ISO equivalent to this standard.
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
E456 Terminology Relating to Quality and Statistics
E682 Practice for Liquid Chromatography Terms and Relationships
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E2935 Practice for Evaluating Equivalence of Two Testing Processes
3. Terminology
3.1 For definitions of terms used in these test methods see 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.
1
This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.22 on Cellular Materials - Plastics
and Elastomers.
Current edition approved April 15, 2017July 1, 2022. Published May 2017July 2022. Originally approved in 2006. Last previous edition approved in 20112017 as
ɛ1
D7252 - 06D7252 - 17.(2011) . DOI:10.1520/D7252-17. DOI:10.1520/D7252-22.
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.
*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

---------------------- Page: 1 ----------------------
D7252 − 22
4. Summary of Test Method
4.1 The sample is reacted (derivatized) with methanol to form a mixture of methyl urethanes. The urethanes mixture is then
separated by normal phase high performance liquid chromatography (HPLC). The separated, derivatized isomers are quantified
through the use of an internal standard.
5. Significance and Use
5.1 This test method is used for research or for quality control to characterize isocyanates used in polyurethane products.
6. Apparatus
6.1 High Performance Liquid Chromatograph, consisting of:
6.1.1 Binary (or greater) solvent pump, capable of maintaining a pulse-free flow rate of 1-3 milliliters per minute
6.1.2 Sample injector, automatic or manual, capable of reproducibly injecting a 2 microliter volume
6.1.3 Column heater, capable of maintaining a temperature of 30 6 0.2°C
6.1.4 UV detector, capable of measurements at 235 nm.
6.1.5 Chart recorder or Data system, capable of peak area integration.
6.2 HPLC analytical column, 250 mm by 4.6 mm by 5 μm cyano stationary phase.
NOTE 2—Other chromatographic columns are used provided it is ascertained that similar chromatographic performance is obtained.
6.3 Magnetic Stirring Hotplate.
7. Reagents and Materials
7.1 Purity of Reagents—Reagent-grade chemicals are to be used in all tests. Unless otherwise indicated, it is intended that all
reagents conform to the specifications of the Committee on Analytical Rea
...