Chemistry:Amine value
In organic chemistry, amine value is a measure of the nitrogen content of an organic molecule.[1] Specifically, it is usually used to measure the amine content of amine functional compounds.[2] 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.[3] Although there are similarities with the method it is not the same as an acid value.
- ASTM D2073 - This is a potentiometric method.[4]
- ASTM D2074-07
- ASTM D2896 - potentiometric method with perchloric acid.[5]
- 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.[6][7][8]
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
- Acid value
- Bromine number
- Epoxy value
- Hydroxyl value
- Iodine value
- Peroxide value
- Saponification value
References
- ↑ Howarth, G.A (1995). "5". in Karsa, D.R. Waterborne Maintenance Systems for Concrete and Metal Structures. 165. Cambridge, U.K: The Royal Society of Chemistry. ISBN 0-85404-740-9.
- ↑ Howarth, GA. Master of Science thesis "The synthesis of a legislation compliant corrosion protection paint system, based on waterborne epoxy, urethane and oxazolidine technology". April 1997 Imperial College London Chapter 1.9.5 page 29
- ↑ "DETERMINING EPOXIDE EQUIVALENT AND AMINE VALUE OF RESINS". https://ftp.dot.state.tx.us/pub/txdot-info/cst/TMS/800-B_series/pdfs/ctm815.pdf.
- ↑ "ASTM D2073 - Standard Test Methods for Total, Primary, Secondary, and Tertiary Amine Values of Fatty Amines, Amidoamines, and Diamines by Referee Potentiometric Method | Engineering360". https://standards.globalspec.com/std/979374/ASTM%20D2073.
- ↑ "Epikure 3378 Technical Data Sheet". https://www.penpoly.com/app/uploads/epikure-3378-tds.pdf.
- ↑ Jackson, M. A (October 1990). "Guidelines to formulation of waterborne epoxy primers". PPCJ Polymers, Paint and Colour Journal 180: 608–617.
- ↑ Howarth, Graham (1995-01-01). "The use of water‐based epoxies for anti‐corrosive primers". Pigment & Resin Technology 24 (6): 3–6. doi:10.1108/eb043156. ISSN 0369-9420.
- ↑ Howarth, GA. Master of Science thesis "The synthesis of a legislation compliant corrosion protection paint system, based on waterborne epoxy, urethane and oxazolidine technology". April 1997 Imperial College London Chapter 3.2.3 Amine stoichiometry page 56
Further reading
- "Amines | Introduction to Chemistry". https://courses.lumenlearning.com/introchem/chapter/amines/#:~:text=The%20amine%20functional%20group%20contains,by%20a%20carbon-containing%20substituent.&text=Amine%20groups%20bonded%20to%20an,are%20known%20as%20aromatic%20amines..
- Epoxy resin technology.. Paul F. Bruins, Polytechnic Institute of Brooklyn. New York: Interscience Publishers. 1968. ISBN 0-470-11390-1. OCLC 182890. https://www.worldcat.org/oclc/182890.
- 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. https://www.worldcat.org/oclc/915134542.
- Lee, Henry (1967). Handbook of epoxy resins. Kris Neville ([2nd, expanded work] ed.). New York: McGraw-Hill. ISBN 0-07-036997-6. OCLC 311631322. https://www.worldcat.org/oclc/311631322.
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