Tertiary 3 aminesin tertiary amines, nitrogen has three organic substituents. Features low temperature curing and high chemical resistance. Grams of hardener containing one equivalent of nh groups. Therefore, 47 parts of epotuf 37703 curing agent are needed to cure 100 parts of the epoxy resin blend. Because the resin is only 30% of the base, the base has an epoxy equivalent weight of 500 geq epoxy. To properly mix this base with an amine hardener having an equivalent weight of 30 g equivalent nh it would be specified that the weight ratio is 30 g amine for every 500 g of epoxy base.
Secondary 2 aminessecondary amines have two organic substituents alkyl, aryl or both bound to the nitrogen together with one hydrogen. A dual mechanism singlecomponent selfhealing strategy for. The stoichiometric mix ratio or the parts by weight of curing agent per 100 parts. Amine hydrogen equivalent weight can be abbreviated as ahew. What is the abbreviation for amine hydrogen equivalent weight. Ahew amine hydrogen equivalent weight all acronyms. This could also be expressed as amine hardener at 6 phr.
The equivalent weight of an element is the mass which combines with or displaces 1. Constituent of ionexchange resins for use in food processing, e. How do we calculate the amount of amine hardener require to. Corrosionpedia what is an amine cured epoxy coating. Note that every time that an epoxy group is opened. Isopropanolamines equivalent weight and amine number. It has similar chemical behavior as ethylene diamine and has similar uses. Oct 29, 20 equivalent weight is a calculated value determined from the amine number also known as the amine value or amine alkalinity. Appendix 1 calculation of stoichiometric weight of curing. Equivalent weight definition is the mass of a substance especially in grams that combines with or is chemically equivalent to eight grams of oxygen or one gram of hydrogen.
Ahew amine hydrogen equivalent weight eew epoxide equivalent weight. Ahew is the amount of curing agent in grams which contains one mole of active. Theoretical equivalent weight of sulfuric acid h 2 so 4 98. Dec 03, 2010 amine hydrogen equivalent weight ahew unit. How do we calculate the amount of amine hardener require to cure. For example, when one molecule of kcl dissolves, it leaves two ions, or charged particles. The equivalent unit was introduced to account for the fact that when solutes dissolve in solvent to create a solution, the number of particles dispersed depends on the valence of the solute. In another exemplary embodiment, an amine functional curing agent has an amine hydrogen functionality ahf of at least 7 and an amine hydrogen equivalent weight ahew of at least about 50. Three different methods for the determination of the amine hydrogen equivalent weight in aliphatic amine epoxide hardeners were compared. Determine the stoichiometric mix ratio in phr of the epoxy resin mixture e. Equivalent weight definition of equivalent weight by.
Jeffamine d230 polyetheramine huntsman corporation. Combined analytical techniques for the determination of the. The amount of heat that is evolved per mole of amine in a neutralization is largely independent of the strength of the amine as a base. How is amine hydrogen equivalent weight abbreviated. Because the material is a polymer and all man made polymers have a polydispersity best slightly greater than 1. Calculating the amine hydrogen equivalent weight for a blend of curing. Primary and secondary amine functional groups contain active hydrogens that will react with an epoxy group and form the final cured thermoset polymer. The desired stoichiometric quantity of amine in weight parts per 100 gram epoxy resin is calculated from the following equation. You must also be able to identify its valence from its molecular formula, as this determines ion number in solution. The amine number is determined by titration of the amine acetate ion by a dilute, typically 1n hcl solution. How do we calculate the amount of amine hardener require.
Combined analytical techniques for the determination of. Ahew amine hydrogen equivalent weight acronymfinder. Two of those methods are based on potentiometric titration. At room temperature however by far the largest groups of chemicals used are amine functional curing agents capable of cross linking epoxy resins at room temperature. I know the amine number of a polymer, and the viscosity. Combined analytical techniques for the determination of the amine. Epoxy curing agents coatings evonik evonik industries. The boiling point of the secondary amine is a little lower than the corresponding primary amine with the same number of carbon atoms.
To calculate the stoichiometric use ratio, the following information is needed. High mechanical strength and temperature resistance. Number of available hydrogens and, of course, one amine hydrogen equivalent weight will react with one equivalent weight of epoxy resin. The amine hydrogen equivalent weight meha was determined for each compound by an indirect method. Amines are multifunctional organic compounds derived from ammonia. The values of the amine hydrogen equivalent weight were calculated from the consumption of hydrobromic acid standard solution during titration according to eq.
Jul 08, 2018 equivalent mass is equal to molecular massacidity in case of base and molecular massbasicity in case of acid and molecular mass valency of metal in case of salt. Aliphatic polyamines can be modified to form a variety of other curatives, including polyamides, polyamineadducts, amidoamines, ketimines and mannich bases. The method is a technique of potentiometric titration in water, the reaction of amine type nitrogen protonation occurred using a standard solution of hydrochloric acid hcl. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. The electronic properties of the substituents alkyl groups enhance the basicity, aryl groups diminish it. Similarly, amine hydrogen equivalent weight ahew in terms of mole is, ahew. Determination of the amine hydrogen equivalent weight in aliphatic. Mw of the hardener divided by the number of active hydrogen per molecule parts per hundred resin phr unit. The hydrogen equivalent is the calculation of the molecular weight of the polymanine divided by the amount of the active hydrogen atom. The meaning of ahew abbreviation is amine hydrogen equivalent weight. Mxdaepoxy resin curing agentsmitsubishi gas chemical co. Determination of the amine hydrogen equivalent weight in aliphatic amine epoxide hardeners by a method of potentiometric titration. Pdf combined analytical techniques for the determination of. A dual mechanism singlecomponent selfhealing strategy.
It is a weak base and its aqueous solution is alkaline. For complete reaction with no unreacted components left over it is important that one equivalent of epoxy must react with one equivalent of nh amine. Amine hydrogen equivalent weight can be abbreviated as ahew definition of ahew ahew stands for amine hydrogen equivalent weight. It is essential to determine the epoxy equivalent weight e. Amine hydrogen equivalent weight, or ahew 60 115 514 81 37 44 250 62 500 pka 9. The amine group nitrogen concentrations estimated for the three hardeners according to the international standard iso 9702. Amine hydrogen equivalent weight how is amine hydrogen equivalent weight abbreviated. As shown by the representative structure, jeffamine d230 polyetheramine is a difunctional, primary amine with an average molecular weight of about 230.
Cloudiness in the sample or test solutions indicates the presence of water. Diethylenetriamine is an analogue of diethylene glycol. What is the abbreviation for aminehydrogen equivalent weight. Important representatives include dimethylamine, while an example of an aromatic amine would be diphenylamine. Secondary amines still form hydrogen bonds, but having the nitrogen atom in the middle of the chain rather than at the end makes. Ahew is defined as amine hydrogen equivalent weight somewhat frequently. Jeffamine d230 polyetheramine is characterized by repeating oxypropylene units in the backbone. Ahew abbreviation stands for amine hydrogen equivalent weight. One of the definitions of ahew is amine hydrogen equivalent weight. The former case applies to acids, which are proton donors, while the second applies to bases, which are proton acceptors. A resin with an equivalent weight of 150 geq epoxy is being mixed with an amine hardener with an equivalent weight of 30 geq amine. The method is a technique of potentiometric titration in water, the reaction of aminetype nitrogen protonation occurred using a standard solution of hydrochloric acid hcl.
Ahew abbreviation stands for aminehydrogen equivalent weight. Amine hydrogen equivalent weight ahew of curing agent ahew molecular weight of amine or 56,100. Amines and chelants are versatile materials that deliver a wide range of performance properties in many different applications and products. Important for the reaction with epoxy resins are only the nitrogen bond hydrogenatom of the primary and secondary amines. See the dow technical bulletin entitled, amine blushing and blooming of epoxy binder systems, form no. October 2014 note 1the presence of water at any time in this procedure will invalidate the results. The primary amine groups are located on secondary carbon. The stoichiometric mix ratio or the parts by weight of curing agent per 100 parts of epoxy resin phr is given by. Many translated example sentences containing amine equivalent weight. Equation 2 phr1 of amine amine h eq wt x 100 epoxide eq wt of resin example phr d. A dual mechanism singlecomponent selfhealing strategy for polymers ling ming meng,a yan chao yuan, a min zhi rongb and ming qiu zhangb a key laboratory for polymeric composite and functional materials of ministry of education, dsapm lab, school of chemistry and chemical engineering, zhongshan university, guangzhou 510275, p. For example, for the bishydroxylphenyl propane epoxy resin with epoxy value at 0.
How can i convert the amine value of an epoxyhardener into the equivalent weight. Mxda has been used as an epoxy curing agent globally for more than 30 years in the paint and coating industry. The combination of the potentiometric methods result in a faster procedure that could be used. How to abbreviate amine hydrogen equivalent weight. To calculate a milliequivalent meq you have to have two pieces of information. A hardener that costs more by weight may be cheaper overall compared to another hardener in cases where its amine hydrogen equivalent has a high value. Appendix 1 calculation of stoichiometric weight of curing agent. Owing to inductive effects, the basicity of an amine might be expected to increase with the number of alkyl groups on the amine. Active application number jp2007519808a other languages japanese ja. Finally, when considering the costs of the hardener, one must consider both the cost by weight and the amine hydrogen equivalent weight. Amine value 255 275 mg kohg iso 9702 amine hydrogen equivalent weight as supplied 175 geq calculated solids content 69 71 wt.
Mxdaepoxy resin curing agentsmitsubishi gas chemical. This definition appears somewhat frequently and is found in the following acronym finder categories. The most common type of epoxy curing agents are based on amines. Two of those methods are based on potentiometric titration and the other one uses differential scanning calorimetry dsc. You can determine the equivalent weight by dividing 56. Determination of the amine hydrogen equivalent weight in. The amine hydrogen equivalent weight of deta is calculated as below. The mass of the substance in question and the molar mass or molecular weight of that substance. Equivalent weight is a calculated value determined from the amine number also known as the amine value or amine alkalinity.
Equivalent weight also known as gram equivalent is the mass of one equivalent, that is the mass of a given substance which will combine with or displace a fixed quantity of another substance. Equivalent weight of amine molecular weight of amine. Methods for accelerating aminecured epoxy systems may include the following. Us8471065b2 high functionality amine compounds and uses. Like ammonia, amines are weak bases, so they work well for neutralizing acidic components and buffering ph in a wide variety of products. Amine value 2,7 ahew 246,9 gmol the epoxy equivalent weight eew of the epoxy resin used allows the correct stoichometric calculation of the amounts to be used. The amine value identify the primary, secondary and tertiary amines. Many translated example sentences containing amine equivalent weight frenchenglish dictionary and search engine for french translations. Amine hydrogen equivalent weight ahew gmol 666,67 amine value example. Mxda chemical structure contributes unique characteristics when used in epoxy, polyamide and urethane systems.
Amine hydrogen equivalent weight how is amine hydrogen. Calculating equivalent weight of epoxy mixtures most formulated products include mixtures of epoxy resins, diluents reactive and unreactive, fillers, additives. In the present work, molecular weight of diethylenetriamine deta is around 103 gmol, number of active hydrogen atoms of deta is 5, molecular weight of the. Note that the primary amine groups in these products are attached to secondary carbon atoms. The list of abbreviations related to ahew amine hydrogen equivalent weight. The phr parts by weight per 100 parts of epoxy resin mixture of the eci polyamine can be determined with the following equation. You need to know the amine hydrogen equivalent weight of deta, and you need the epoxy equivalent weight of the epoxy resin. The number of milligrams of potassium hydroxide equivalent to the amine basicity in 1 g of sample. The degree of solvation of the protonated amine, which includes steric hindrance by the groups on nitrogen electronic effects.
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