ASTM D4274-23

Standard Test Methods for Testing Polyurethane Raw Materials: Determination of Hydroxyl Numbers of Polyols

SIGNIFICANCE AND USE
5.1 These test methods are suitable for research and as quality control and specification tests. It is necessary to know the hydroxyl contents of polyols in order to formulate polyurethane systems.
SCOPE
1.1 These test methods measure the hydroxyl groups in polyester and polyether polyols containing primary and secondary hydroxyl groups. They also apply to many other hydroxyl-containing substances.  
1.1.1 Test Method A—Acetic Anhydride Pressure Bottle, recommended for polyesters.  
1.1.2 Test Method B—Phthalic Anhydride Pressure Bottle, recommended for polyethers and polyesters.  
1.1.3 Test Method C—Phthalic Anhydride Reflux, recommended for polyethers and polyesters.  
1.1.4 Test Method D—Imidazole–Catalyzed Phthalic Anhydride Pressure Bottle, recommended for polyethers, polyesters, polymer polyols, and amine-initiated polyols.  
1.1.5 Test Method E—Imidazole-Catalyzed Pyromellitic Dianhydride Esterification, recommended for polyols used for flexible and rigid polyurethane foams and urethane elastomers. It is recommended for polyester polyols, polyether polyols, amine-started polyols, and polymer polyols (polyacrylonitrile/copolystyrene-based).  
1.2 Another ASTM test method for measuring hydroxyl groups is Test Method E222.  
1.3 The values stated in SI units are to be regarded as the standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
Note 1: This standard, ISO 14900 and ISO 6796 address the same subject matter, but differ in technical content.  
1.5 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: 83.080.20 - Thermoplastic 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: D4274 − 23
Standard Test Methods for Testing
Polyurethane Raw Materials: Determination of Hydroxyl
1
Numbers of Polyols
This standard is issued under the fixed designation D4274; 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* Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.1 These test methods measure the hydroxyl groups in
Barriers to Trade (TBT) Committee.
polyester and polyether polyols containing primary and sec-
ondary hydroxyl groups. They also apply to many other
2. Referenced Documents
hydroxyl-containing substances.
2
2.1 ASTM Standards:
1.1.1 Test Method A—Acetic Anhydride Pressure Bottle,
D883 Terminology Relating to Plastics
recommended for polyesters.
D1193 Specification for Reagent Water
1.1.2 Test Method B—Phthalic Anhydride Pressure Bottle,
E180 Practice for Determining the Precision of ASTM
recommended for polyethers and polyesters.
Methods for Analysis and Testing of Industrial and Spe-
1.1.3 Test Method C—Phthalic Anhydride Reflux, recom-
3
cialty Chemicals (Withdrawn 2009)
mended for polyethers and polyesters.
E200 Practice for Preparation, Standardization, and Storage
1.1.4 Test Method D—Imidazole–Catalyzed Phthalic Anhy-
of Standard and Reagent Solutions for Chemical Analysis
dride Pressure Bottle, recommended for polyethers, polyesters,
E203 Test Method for Water Using Volumetric Karl Fischer
polymer polyols, and amine-initiated polyols.
Titration
1.1.5 Test Method E—Imidazole-Catalyzed Pyromellitic Di-
E222 Test Methods for Hydroxyl Groups Using Acetic
anhydride Esterification, recommended for polyols used for
Anhydride Acetylation
flexible and rigid polyurethane foams and urethane elastomers.
E456 Terminology Relating to Quality and Statistics
It is recommended for polyester polyols, polyether polyols,
E691 Practice for Conducting an Interlaboratory Study to
amine-started polyols, and polymer polyols (polyacrylonitrile/
Determine the Precision of a Test Method
copolystyrene-based).
E2935 Practice for Evaluating Equivalence of Two Testing
1.2 Another ASTM test method for measuring hydroxyl
Processes
groups is Test Method E222. 4
2.2 ISO Standard:
1.3 The values stated in SI units are to be regarded as the ISO 6796 Polyglycols for Industrial Use—Determination of
standard. Hydroxyl Number—Phthalic Anhydride Esterification
Method
1.4 This standard does not purport to address all of the
ISO 14900 Plastics—Polyols for Use in the Production of
safety concerns, if any, associated with its use. It is the
Polyurethane—Determination of Hydroxyl Number
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
3. Terminology
mine the applicability of regulatory limitations prior to use.
3.1 Definitions—Terms used in this standard are defined in
NOTE 1—This standard, ISO 14900 and ISO 6796 address the same
accordance with Terminology D883, unless otherwise speci-
subject matter, but differ in technical content.
fied. For terms relating to precision and bias and associated
1.5 This international standard was developed in accor-
issues, the terms used in this standard are defined in accordance
dance with internationally recognized principles on standard-
with Terminology E456.
ization established in the Decision on Principles for the
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
1
These test methods are under the jurisdiction of ASTM Committee D20 on Standards volume information, refer to the standard’s Document Summary page on
Plastics and is the direct responsibility of Subcommittee D20.22 on Cellular the ASTM website.
3
Materials - Plastics and Elastomers. The last approved version of this historical standard is referenced on
Current edition approved March 15, 2023. Published March 2023. Originally www.astm.org.
4
approved in 1988. Last previous edition approved in 2021 as D4274 - 21. DOI: Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
10.1520/D4274-23. 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

---------------------- Page: 1 ----------------------
D4274 −
...

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: D4274 − 21 D4274 − 23
Standard Test Methods for Testing
Polyurethane Raw Materials: Determination of Hydroxyl
1
Numbers of Polyols
This standard is issued under the fixed designation D4274; 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 hydroxyl groups in polyester and polyether polyols containing primary and secondary
hydroxyl groups. They also apply to many other hydroxyl-containing substances.
1.1.1 Test Method A—Acetic Anhydride Pressure Bottle, recommended for polyesters.
1.1.2 Test Method B—Phthalic Anhydride Pressure Bottle, recommended for polyethers and polyesters.
1.1.3 Test Method C—Phthalic Anhydride Reflux, recommended for polyethers and polyesters.
1.1.4 Test Method D—Imidazole–Catalyzed Phthalic Anhydride Pressure Bottle, recommended for polyethers, polyesters, polymer
polyols, and amine-initiated polyols.
1.1.5 Test Method E—Imidazole-Catalyzed Pyromellitic Dianhydride Esterification, recommended for polyols used for flexible
and rigid polyurethane foams and urethane elastomers. It is recommended for polyester polyols, polyether polyols, amine-started
polyols, and polymer polyols (polyacrylonitrile/copolystyrene-based).
1.2 Another ASTM test method for measuring hydroxyl groups is Test Method E222.
1.3 The values stated in SI units are to be regarded as the standard.
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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
NOTE 1—This standard, ISO 14900 and ISO 6796 address the same subject matter, but differ in technical content.
1.5 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.
1
These test methods are 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 July 1, 2021March 15, 2023. Published July 2021March 2023. Originally approved in 1988. Last previous edition approved in 20162021 as
D4274 - 16.D4274 - 21. DOI: 10.1520/D4274-21.10.1520/D4274-23.
*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 ----------------------
D4274 − 23
2. Referenced Documents
2
2.1 ASTM Standards:
D883 Terminology Relating to Plastics
D1193 Specification for Reagent Water
E180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals
3
(Withdrawn 2009)
E200 Practice for Preparation, Standardization, and Storage of Standard and Reagent Solutions for Chemical Analysis
E203 Test Method for Water Using Volumetric Karl Fischer Titration
E222 Test Methods for Hydroxyl Groups Using Acetic Anhydride Acetylation
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
4
2.2 ISO Standard:
ISO 6796 Polyglycols for Industrial Use—Determination of Hydroxyl Number—Phthalic Anhydride Esterification Method
ISO 14900 Plastics—Polyols for Use in the Production of Polyurethane—Determination of Hydroxyl Number
3. Terminology
3.1 Definitions—Terms 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—There are no terms in these test methods that require new or other than
dictionary definitions.
4. Summary of Test Methods
4.1 Test Method A—The sample is acetylated with a solution of acetic anhydride in pyridine in a pressure bottle at 98°C. The
ex
...