Amine value
In organic chemistry, amine value is a measure of the nitrogen content of an organic molecule. Specifically, it is usually used to measure the amine content of amine functional compounds. It may be defined as the number of milligrams of potassium hydroxide (KOH) equivalent to one gram of epoxy hardener resin. The units are thus mg KOH/g.
List of ASTM methods
There are a number of ASTM analytical test methods to determine amine value. A number of states in the United States have adopted their own test methods but they are based on ASTM methods. Although there are similarities with the method it is not the same as an acid value.
- ASTM D2073 - This is a potentiometric method.
- ASTM D2074-07
- ASTM D2896 - potentiometric method with perchloric acid.
- ASTM D6979-03
First principles
The amine value is useful in helping determine the correct stoichiometry of a two component amine cure epoxy resin system.
It is the number of Nitrogens x 56.1 (Mwt of KOH) x 1000 (convert to milligrams) divided by molecular mass of the amine functional compound. So using Tetraethylenepentamine (TEPA) as an example: Mwt = 189, number of nitrogen atoms = 5
So 5 x 1000 x 56.1/189 = 1484. So the Amine Value of TEPA = 1484
Other amines
All numbers are in units of mg KOH/g.
- Ethylenediamine. Amine value = 1870
- Diethylenetriamine. Amine value = 1634
- Triethylenetetramine. Amine value = 1537
- Aminoethylpiperazine. Amine value = 1305
- Isophorone diamine. Amine value = 660
- Hexamethylenediamine. Amine value = 967
- 1,2-Diaminocyclohexane. Amine value = 984
- 1,3-BAC. Amine value = 790
- 2-Methylpentamethylenediamine -Dytek A. Amine value = 967
- m-Xylylenediamine -MXDA. Amine value = 825
See also-related test methods
References
Further reading
- "Amines | Introduction to Chemistry". courses.lumenlearning.com. Retrieved 2021-07-22.
- Epoxy resin technology. Paul F. Bruins, Polytechnic Institute of Brooklyn. New York: Interscience Publishers. 1968. ISBN 0-470-11390-1. OCLC 182890.
{{cite book}}: CS1 maint: others (link) - Flick, Ernest W. (1993). Epoxy resins, curing agents, compounds, and modifiers : an industrial guide. Park Ridge, NJ. ISBN 978-0-8155-1708-5. OCLC 915134542.
{{cite book}}: CS1 maint: location missing publisher (link) - Lee, Henry (1967). Handbook of epoxy resins. Kris Neville ([2nd, expanded work] ed.). New York: McGraw-Hill. ISBN 0-07-036997-6. OCLC 311631322.