Diammonium adipate

Bromohexane 27213-78-1 Butyl Catechol (tert-) 3323-53-3 Hexamethylene Diammonium Adipate... 

A portion of the adipic acid is converted into hexamethylene diamine. A mixture of adipic acid and ammonia is passed over silica gel or boron phosphate at a temperature in the range of 350 to 400 C. During the course of the reaction diammonium adipate is formed which is converted to adipamide and this, in turn, loses water yielding adiponitrile ... 

In the nylon 66 sujterpolyamide molecule there are equal numliers of adipic acid and hexamethylene diamine molecules. To ensure that the components are balanced the first stage in polymerization consists of preparing hexamethylene diammonium adipate, which is conMuonly called nylon 66 salt. 

Nyloprint, of BASF is a solid type of photosensitizer compound coated plate, around 1967. The solid photopolymerizing material is a combination of an alcohol-soluble polyamide (such as a polyamide copolymer of hexamethylene diammonium adipate and e-caprolactam), a vinyl monomer (such as bis-acrylamide, hexamethylene bis-acrylamide, triethylene glycol diacrylate, etc.), a photo-initiator such as benzoin methyl ether, and an inhibitor (such as hydroquinone) and maleic anhydride to function as a... 

Salt dehydration. Direct esterification requires high purity materials in equimolar amounts because esterifications rarely go beyond 98% completion in practice. To overcome this, hexamethylene diamine and a dibasic acid such as adipic acid can be reacted to produce a nylon salt, hexamethylene diammonium adipate. A solution of 0.5-mol diamine in a mixture of 95% ethanol (160 cm ) and distilled water (60 cm ) is added to 0.5-mol diacid dissolved in 600 cm of 95% ethanol over a period of 15 min. The mixture is stirred for 30 min during which time the nylon salt precipitates as a white crystalline solid. This can be recrystallized and should melt at 456 K. The pure salt can be converted into a polyamide by heating it under vacuum in a sealed tube, protected by wire gauze, at about 540 K in the presence of a small quantity of the diacid, e.g., 10 g salt to 0.55-g adipic acid is a suitable mixture. If a lower molar mass is desired, a monofunctional acid can replace the adipic acid and act as a chain terminator. 

The main issue in condensation polymerization is the retention of equivalent concentrations of both contra-functional groups (COOH and NH2), because an excess of either one eventually decreases the chain length significantly. Hence it is customary to react both monomers in a first stage forming a Nylon salt (hexa-methylene diammonium adipate) as an aqueous solution which is conveniently stored or transported. Polymerization is carried out in a stirred tank (autoclave), either batchwise or continuously, at pressures up to 20 atmospheres and temperature of 200 C to 275 C. 

C10H22N2O1, Tetramethylene diammonium adipate, 26, 644 C12H22/ trans-Polydodecenamer, 32B, 46... 

Nylon 66 is manufactured by polycondensation of hexam-ethylenediamine and adipic acid usually in a multistage process. First, nylon salt hexamethylene diammonium adipate is prepared from stoichiometric quantities of hexamethylene-diamine and adipic acid in water. The salt can easily be separated by precipitation with methanol ... 

The preferred method for preparing polyamides from diamines and diacids is melt polymerization of the corresponding nylon salt. For example, in the preparation of nylon 6.6, hexamethylene diamine and adipic acid are first reacted together at low temperature to form hexamethylene diammonium adipate (nylon 6.6 salt) which then is purified by recrystallization. The salt is heated gradually up to about 550 K to effect melt polymerization and maintained at this temperature whilst removing the water produced as steam... 

In the first process adipic acid was converted to adiponitrile by a high temperature reaction with ammonia over a boron phosphate catalyst at temperatures in the range 300-350°C. The process was thought to proceed via the formation of diammonium adipate, followed by dehydration to adiponitrile ... 

Information about SSP of aliphatic polyamides was for the first time disclosed in a patent of DuPont [27] concerning Nylon-6,6. In this patent, polycondensation of hexamethylene diammonium adipate (AH-salt) was initially conducted in the... 

Amidation. Heating of the diammonium salt or reaction of the dimethyl ester with concentrated ammonium hydroxide gives adipamide [628-94-4] mp 228°C, which is relatively insoluble in cold water. Substituted amides are readily formed when amines are used. The most industrially significant reaction of adipic acid is its reaction with diamines, specifically 1,6-hexanediamine. A water-soluble polymeric salt is formed initially upon mixing solutions of the two materials then hea ting with removal of water produces the polyamide, nylon-6,6. This reaction has been studied extensively, and the hterature contains hundreds of references to it and to polyamide product properties (31). 

Nylons are polyamides formed by step-growth polymerization. In Section 22.16A, we learned that nylon 6,6 can be prepared by the reaction of a diacid chloride and a diamine. Nylon 6,6 can also be prepared by heating adipic acid and 1,6-diaminohexane. A Br0nsted-Lowry acid-base reaction forms a diammonium salt, which loses H2O at high temperature. In both methods, each starting material has two identical functional groups. 

See Diisobutyl adipate Hexanedioic acid, compd. with 1,6-hexanediamine (1 1). See Hexamethylenediamine adipate Hexanedioic acid, diamide. See Adipamide Hexanedioic acid, diammonium salt. See Ammonium adipate... 

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