ASTM D1652-11(2019)

Standard Test Method for Epoxy Content of Epoxy Resins

SIGNIFICANCE AND USE
4.1 The epoxy content of epoxy resins is an important variable in determining their reactivity and the properties of coatings made from them. These test methods may be used to determine the epoxy content of manufactured epoxy resins and confirm the stated epoxy content of purchased epoxy resins.
SCOPE
1.1 This test method covers the procedure for manual and automatic titration of epoxy resins for the quantitative determination of the percent epoxide content from 0.1 to 26 % epoxide.  
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
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. For specific hazard statements, see Section 6.  
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: 31-May-2019
• ICS: 83.080.10 - Thermosetting materials
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.33 - Polymers and Resins

Relations

• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D1193-99e1 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Refers: ASTM D1193-99 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999

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: D1652 − 11 (Reapproved 2019)
Standard Test Method for
Epoxy Content of Epoxy Resins
This standard is issued under the fixed designation D1652; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope directly or in situ. The hydrogen bromide reacts stoichiometri-
cally with epoxy groups to form bromohydrins; therefore, the
1.1 This test method covers the procedure for manual and
quantity of acid consumed is a measure of the epoxy content.
automatic titration of epoxy resins for the quantitative deter-
3.1.1 In the Manual Titration Method, the titration is with
mination of the percent epoxide content from 0.1 to 26 %
standard perchloric acid in the presence of an excess of
epoxide.
tetraethylammonium bromide. Hydrogen bromide generated in
1.2 The values stated in SI units are to be regarded as the
situ by the addition of perchloric acid to the quaternary
standard. The values given in parentheses are for information
ammonium halide rapidly opens the oxirane ring.
only.
3.1.2 In the Automatic Titration Method, the reaction is
1.3 This standard does not purport to address all of the
measuring the millivolt (MV) potential as perchloric acid is
safety concerns, if any, associated with its use. It is the
added, which combines with the bromide to form the hydro-
responsibility of the user of this standard to establish appro-
bromic acid, which reacts with the epoxide group. As the
priate safety, health, and environmental practices and deter-
reaction progresses, the potential will gradually increase until
mine the applicability of regulatory limitations prior to use.
the reaction nears completion at which point the potential
For specific hazard statements, see Section 6.
increases very quickly. The titrator measures the rate of the
1.4 This international standard was developed in accor-
reaction by calculating the change in potential between per-
dance with internationally recognized principles on standard-
chloric acid addition increments. When the change in potential
ization established in the Decision on Principles for the
begins to decrease, the titrator determines that the titration is
Development of International Standards, Guides and Recom-
complete. The epoxide content is calculated using the reagent
mendations issued by the World Trade Organization Technical
factor entered by the user during standardization, the weight of
Barriers to Trade (TBT) Committee.
the sample, and the volume of perchloric acid added during
titration.
2. Referenced Documents
2.1 ASTM Standards:
4. Significance and Use
D1193 Specification for Reagent Water
4.1 The epoxy content of epoxy resins is an important
2.2 Other Documents:
variable in determining their reactivity and the properties of
OSHA Regulations, 29 CFR paragraphs 1910.1000 and
coatings made from them. These test methods may be used to
1910.1200
determine the epoxy content of manufactured epoxy resins and
confirm the stated epoxy content of purchased epoxy resins.
3. Summary of Test Method
3.1 The resin is dissolved in a suitable solvent and the
5. Reagents
resulting solution is titrated with hydrogen bromide either
5.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated, it is intended that
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of all reagents shall conform to the specifications of the Commit-
Subcommittee D01.33 on Polymers and Resins.
tee onAnalytical Reagents of theAmerican Chemical Society,
Current edition approved June 1, 2019. Published June 2019. Originally 4
where such specifications are available. Other grades may be
ɛ1
approved in 1969. Last previous edition approved in 2011 as D1652 – 11 . DOI:
10.1520/D1652-11R19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Reagent Chemicals, American Chemical Society Specifications, American
Standards volume information, refer to the standard’s Document Summary page on Chemical Society, Washington, DC. For suggestions on the testing of reagents not
the ASTM website. listed by the American Chemical Society, see Analar Standards for Laboratory
AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments, Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:// and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
www.access.gpo.gov. MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1652 − 11 (2019)
used, provided it is first ascertained that the reagent is of 10. Standardization of 0.1N Perchloric Acid Reagent
sufficiently high purity to permit its use without lessening the
10.1 Standardization with Potassium Hydrogen Phthalate:
accuracy of the determination.
10.1.1 Dissolve 0.4 g of potassium hydrogen phthalate,
5.2 Purity of Water—Unless otherwise indicated, references weighed accurately to the nearest milligram, in 50 mL of
to water shall be understood to mean reagent water as defined glacial acetic acid, and add 6 to 8 drops of crystal violet
by Type II of Specification D1193. indicator solution. Insert a clean stirring bar into the sample,
and adjust the magnetic stirrer to effect solution. Continue
6. Hazards
agitation throughout the titration procedure. Titrate with per-
6.1 Hydrogen bromide and glacial acetic acid are corrosive. chloric acid reagent solution to the end point, which is a sharp
Chlorobenzene and chloroform are considered hazardous. In change in color from blue to green, stabilize for at least 2 min.
addition to other precautions, take care to avoid inhalation and 10.1.2 Calculate and record the perchloric acid reagent
skin or eye contact with these chemicals. Use goggles or a face
normality as follows:
shield, or both. Protect skin by use of suitable protective
N 5 ~W 31000!/~204.2 3 V! (1)
clothing. All specimen preparations shall be done in a well
where:
ventilated area, such as a fume hood.
N = normality of perchloric acid reagent,
6.2 Consult current OSHARegulations, Supplier’s Material
W = potassium hydrogen phthalate used, g, and
Safety Data Sheets, and local regulations for all materials used
V = volume of perchloric acid reagent required to titrate
in this test method.
the standard, mL.
Manual Titration for Epoxy Content of Epoxy Resins
10.2 Standardization with Potassium Hydrogen Phthalate:
10.2.1 Dissolve 0.25 to 0.40 g of the potassium hydrogen
7. Apparatus
phthalate accurately weighed to the nearest milligram into a 2
7.1 Buret, closed-reservoir type, bottom filling, 25-mL with
oz wide-mouth bottle or 100 mL disposable beaker. Add 40 to
⁄10-mL division, or potentiometric automatic titrator.
50 mL of glacial acetic acid. Insert a clean stirring bar into the
sample and adjust the magnetic stirrer to effect solution.
7.2 Erlenmeyer Flasks, 100-mL, 250-mL, and 500-mL.
Continue agitation throughout the titration procedure.
7.3 Magnetic Stirrer, adjustable speed.
10.2.2 Add 10 mL of tetraethylammonium bromide reagent
7.4 Magnetic Stirring Bars, polytetrafluoroethylene (PTFE)
and 6 to 8 drops of crystal violet indicator solution and titrate
coated.
to a sharp blue-to-green end point with the perchloric acid
r
...