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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.Howarth, GA. Master of Science thesis "The synthesis of a legislation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Chemistry
Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; Greeves, N. and Warren, S. (2012) ''Organic Chemistry''. Oxford University Press. pp. 1–15. . Study of structure determines their structural formula. Study of properties includes Physical property, physical and Chemical property, chemical properties, and evaluation of Reactivity (chemistry), chemical reactivity to understand their behavior. The study of organic reactions includes the organic synthesis, chemical synthesis of natural products, drugs, and polymers, and study of individual organic molecules in the laboratory and via theoretical (in silico) study. The range of chemicals studied chemistry includes hydrocarbons (compounds containing only carbon and hydrogen) as well as compounds based on carbon, but a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aminoethylpiperazine
Aminoethylpiperazine (AEP) is a derivative of piperazine. This ethyleneamine contains three nitrogen atoms; one primary, one secondary and one tertiary. It is a corrosive organic liquid and can cause second or third degree burns. Aminoethylpiperazine can also cause pulmonary edema as a result of inhalation. It is REACH and TSCA registered. Production Ethylene dichloride is reacted with ammonia as a main method of production. This process produces various ethylene amines which can then be purified by distillation. These include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, other higher homologues and aminoethyl piperazine. AEP is also manufactured by reacting ethylenediamine or ethanolamine/ammonia mixtures over a catalyst. Epoxy resin curing agent A key use of AEP is as an epoxy curing agent. When used as an epoxy resin curing agent, it is usually used in conjunction with other amines as an accelerator as it only has 3 amine hydrogens for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxide Value
Detection of peroxide gives the initial evidence of rancidity in unsaturated fats and oils. Other methods are available, but peroxide value is the most widely used. It gives a measure of the extent to which an oil sample has undergone primary oxidation; extent of secondary oxidation may be determined from p-anisidine test.Chemistry And Technology Of Oils And FatChemistry And Technology Of Oils And Fats By Dr. M.M. Chakrabarty The double bonds found in fats and oils play a role in autoxidation. Oils with a high degree of Unsaturated fat, unsaturation are most susceptible to autoxidation. The best test for autoxidation (oxidative rancidity) is determination of the peroxide value. Peroxides are intermediates in the autoxidation reaction. Autoxidation is a Free radical addition, free radical reaction involving oxygen that leads to deterioration of fats and oils which form off-flavours and off-odours. Peroxide value, concentration of peroxide in an oil or fat, is useful for assessing t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodine Value
In chemistry, the iodine value (IV; also iodine absorption value, iodine number or iodine index) is the mass of iodine in grams that is consumed by 100 grams of a chemical substance. Iodine numbers are often used to determine the degree of unsaturation in fats, oils and waxes. In fatty acids, unsaturation occurs mainly as double bonds which are very reactive towards halogens, the iodine in this case. Thus, the higher the iodine value, the more unsaturations are present in the fat. It can be seen from the table that coconut oil is very saturated, which means it is good for making soap. On the other hand, linseed oil is highly unsaturated, which makes it a drying oil, well suited for making oil paints. Principle The determination of iodine value is a particular example of iodometry. A solution of iodine is yellow/brown in color. When this is added to a solution to be tested, however, any chemical group (usually in this test double bonds) that react with iodine effectiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxyl Value
In analytical chemistry, the hydroxyl value is defined as the number of milligrams of potassium hydroxide (KOH) required to neutralize the acetic acid taken up on acetylation of one gram of a chemical substance that contains free hydroxyl groups. The analytical method used to determine hydroxyl value traditionally involves acetylation of the free hydroxyl groups of the substance with acetic anhydride in pyridine solvent. After completion of the reaction, water is added, and the remaining unreacted acetic anhydride is converted to acetic acid and measured by titration with potassium hydroxide. The hydroxyl value can be calculated using the following equation. Note that a chemical substance may also have a measurable acid value affecting the measured endpoint of the titration. The acid value () of the substance, determined in a separate experiment, enters into this equation as a correction factor in the calculation of the hydroxyl value (): ::\mathrm = \frac + \mathrm Where i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxy Value
Epoxy value derives from the Epoxy equivalent weight (EEW) or Weight Per Epoxide (WPE) and is a measure of the epoxy content of an epoxy resin or epoxy reactive diluent, or glycidyl ether. This is an important parameter as it allows determination of the correct mix ratio of an epoxy system with a curing agent. The epoxide equivalent weight is usually measured first and done by titration. The standard test method is ASTM D1652 though this has been modified by certain states of the USA. The epoxy equivalent weight (EEW) maybe defined as: the number of grams of epoxy resin required to give 1 mole of epoxy groups. The epoxy value is defined as the number of moles of epoxy group per 100g resin. Example calculations Polyoxypropylene diglycidyl ether, a reactive diluent with the trade name of Diluent F, has an average molecular weight of 1000 and a functionality of 2 so the EEW is 1000/2 = 500. The epoxy value is defined as the number of moles of epoxy group per 100g resin. So as an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromine Number
In chemistry, the bromine number is the amount of bromine () in grams absorbed by 100 g of a sample. The bromine number was once used as a measure of aliphatic unsaturation in gasoline and related petroleum samples, but this assay has fallen into disuse with the introduction of spectroscopic and chromatographic analyses. Concept It is based on the following reaction: : Bromine is deeply colored but is not. Thus, the consumption of bromine can often be gauged visually. Alternatively and more quantitatively, the bromine consumed by a sample can be determined by iodometry. The bromine number indicates the degree of unsaturation of a sample. The technique can be subject to a variety of problems, whereby the sample consumes more or less bromine than predicted by the equation above. For example, some alkenes dimerize in the presence of bromine. Allylic bromination is another problem. The bromine number is similar to the iodine number, which is a similar technique used in evaluatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid Value
In chemistry, acid value (AV, acid number, neutralization number or acidity) is a number used to quantify the acidity of a given chemical substance. It is the quantity of Base (chemistry), base (usually potassium hydroxide (KOH)), expressed as milligrams of KOH required to Neutralization (chemistry), neutralize the acidic constituents in 1 gram of a sample. The acid value measures the acidity of water-insoluble substances like oils, fats, waxes and resins, which do not have a pH value. The acid number is a measure of the number of carboxylic acid groups () in a chemical compound, such as a fatty acid, or in a mixture of compounds. In other words, it is a measure of free fatty acids (FFAs) present in a substance. In a typical procedure, a known amount of sample dissolved in an organic solvent (often isopropyl alcohol, isopropanol) and titration, titrated with a solution of alcoholic potassium hydroxide (KOH) of known concentration using phenolphthalein as a colour indicator. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M-Xylylenediamine
''m''-Xylylenediamine is an organic compound with the formula C6H4(CH2NH2)2. A colorless oily liquid, it is produced by hydrogenation of isophthalonitrile. Uses and reactions ''m''-Xylylenediamine (MXDA) is used in a variety of industrial applications including amine based curing agents for epoxy resins which may then be formulated into coatings, adhesives, sealants, and elastomers. ''m''-Xylylenediamine undergoes the Sommelet reaction to give isophthalaldehyde. Hazards Exposure to ''m''-xylylenediamine may occur by inhalation, skin contact, eye exposure, or ingestion. It can cause chemical burns, tissue damage, delayed pulmonary edema, shock, and skin sensitization. Symptoms of inhalation include a burning sensation in the respiratory tract, cough, sore throat, labored breathing, and dyspnea (shortness of breath). It is also flammable and produces toxic fumes when burned. ''m''-Xylylenediamine reacts with acids, acid chlorides, and acid anhydride An acid anhydride is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-Methylpentamethylenediamine
2-Methylpentamethylenediamine is an organic compound part of the amine family with the formula H2NCH2CH2CH2CH(CH3)CCH2NCH2. A colorless liquid, this diamine is obtained by the hydrogenation of 2-methylglutaronitrile. It is better known by the trade name "Dytek A". Uses 2-Methylpentamethylenediamine can serve as a curing agent for epoxy resin systems. It gives good adhesion to metals and resistance against corrosion and other chemicals. It provides toughness, low blush, uniform finish, high gloss, and improves UV stability. It reduces gel time and is compatible with epoxy resins. It is suitable for marine, industrial, and decorative coatings. 2-Methylpentamethylenediamine can also be used as a chain extender for polyurethane applications, and in particular with PUDs. Its derivatives like aspartic esters, secondary amines, aldimines and ketoimines serve as curatives in polyurea systems. In polyamides, 2-Methylpentamethylenediamine acts as a crystallinity disruptor. This makes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,3-BAC
1,3-bis(aminomethyl)cyclohexane (1,3-BAC) are a collection of organic compounds with the formula . The compounds belong to the sub class cycloaliphatic amine. Their key use is as an epoxy resin curing agent. Manufacture It has been produced commercially as part of a mixture with the 1,4 derivative. The primary route of manufacture is by catalytic hydrogenation of ''m''-xylylenediamine usually called MXDA. Uses Like most amines it maybe used as an epoxy curing agent. However, the presence of the amino group also means it can be used in polyurethane chemistry by reacting with isocyanates. In this case a polyurea would be produced. It may also be reacted with phosgene (phosgenation) to produce an isocyanate. Safety It is corrosive with a Packing Group I designation. See also * DCH-99 * Epoxy Epoxy is the family of basic components or Curing (chemistry), cured end products of epoxy Resin, resins. Epoxy resins, also known as polyepoxides, are a class of reactive pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
