Amine_value Knowpia

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 edit

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 edit

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 edit

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

References edit

^ Howarth, G.A (1995). "5". In Karsa, D.R; Davies, W.D (eds.). Waterborne Maintenance Systems for Concrete and Metal Structures. Vol. 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" (PDF). Texas.gov.
^ "ASTM D2073 - Standard Test Methods for Total, Primary, Secondary, and Tertiary Amine Values of Fatty Amines, Amidoamines, and Diamines by Referee Potentiometric Method | Engineering360". standards.globalspec.com. Retrieved 2021-07-22.
^ "Epikure 3378 Technical Data Sheet" (PDF). Peninsula Polymers.
^ Jackson, M. A (October 1990). "Guidelines to formulation of waterborne epoxy primers". PPCJ Polymers, Paint and Colour Journal. 180: 608–617 – via DMG Events.
^ 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