Amine neutralization

Neutralizing Amines. Neutralizing amines are used to neutralize the acid (H" ) generated by the dissolution of carbon dioxide or other acidic process contaminants in the condensate. These amines hydrolyze when added to water and generate the hydroxide ions required for neutralization ... 

Demand for amine (neutralization capacity) is determined by C02 loading and amine equivalent weight. Polyfunctional amines appear to have a large equivalent weight advantage, but in practice they often have very low volatility and poor thermal stability. 

Acid value/H2S04a Potentiometric titration Acid amine neutralization in nonaqueous medium... 

In 1970, Monroe and Rooker(28) claimed the use of aluminum salts of acid orthophosphate esters as viscosity builders for use in fracturing fluids. The application of these materials began a new era of hydrocarbon gelling agents. Monroe(29) later claimed the use of Fe30it as a metal activator of phosphate esters and in 1971 described several other metals(30) that could be used with amine neutralization agents. Numerous metallic ionic derivatives can be used as effective "activators" or crosslinkers to prepare a gel. 

Table 3.16 Ionic conductivity (25°C) of amines neutralized by HBF4. Data from Ref. [n8]...

TABLE 16.1 Structures of tertiary amines, melting points, and ionic conductivities for tertiary amines neutralized with an equimolar amount of HTFSI... 

Table 19.1 shows the characteristics of several amines neutralized with HBF4. The BF4 salts cannot be prepared by the acid ester method and are water soluble. Also very pure BF4 salts are extremely difficult to prepare. However, it is quite easy to get salts by neutralizing the tertiary amines with HBF4. 

The amines neutralized with HBF4 are stable. They show no weight loss up to 250°C, and the decomposition temperature depends on the starting tertiary amines. This is a remarkable improvement in stability. The melting point (T ) of neutralized amines is not a simple function of the molar mass of the starting amines, however. The Tm of the starting amines can affect the Tm of the salts. Figure 19.1 shows... 

TABLE 19.1 Thermal Behavior of Amines Neutralized with HBF4... 

Knox, J.H. and Hartwick, R.A. Mechanism of ion-pair liquid chromatography of amines, neutrals, zwitterions and acids using anionic hetaerons. /. Chmmatogr. 1981, 204, 3-21. 

A number of other delignilicatioii procedures have been devised in which the primary objective has been to obtain, for various purposes, a measure of the total-carbohydrate fraction. These procedures have employed as the active delignifyiiig agents such materials as nitric acid, monoethanola-miiie H. 178 other amines, neutral hypochlorite, acid hypochlorite, etc. These methods have recently been discussed by Browning and by Jahn. Although such procedures are of general interest, their application has not yielded much information that could be considered fundamental to an understanding of the chemistry of wood cellulose. Neither have these procedures become important in the commercial production of wood cellulose. 

Fig. 2. Dependence of second-order rate constant for formohydroxamic acid formation (fca = fcoi,i/[NHaOH]) on hydroxylamine concentration at different fractions of hydroxyl-amine neutralization at 39°, ionic strength 2-0. The heavy lines were calculated from the steady-state equation. From Jencks and Gilchrist (1964a). Reproduced with permission of the American Chemical Society.

One case, however, seems clear. Ammonia and amines do react with ordinary esters to give amides, and it is known84 that the attack at the carbonyl group is rate-determining and effectively irreversible above pH7. Ammonia and amines (neutral and therefore relatively soft nucleophiles) in methanol react with acrylic ester (100) at the /J-position.85... 

Tris-[2-methyl-propyl]-amin(neutral) Benzyl-dimethyl-amin (pH 10,3) Bis-[3,4-mcthylendioxy-benzyl]-me-thyl-amin (50% H2S04) Dibenzyl-(4-methoxy-benzyl)-amin (50% H2S04)... 

Water retention determines the mechanical properties of films in general and of water-dispersible coatings in particular. Coincident with the increased water retention of poly(acrylic acid), the rigidity modulus of partially amine-neutralized solutions (0 < a <... 

Adogen MA, S. [Sherex] Dimethyl amines neutralizer, conditioner, coemulsifier. 

Aqueous solutions of sodium nitrite (4.5) and of acetic acid (4 g) are added successively to one of bicyclo[3.2.2]nonane-6-methylamine hydrochloride (13 g) in water (50 ml) while a rapid stream of steam is passed through the solution. When this reaction ceases, further sodium nitrite (2 g) and acetic acid (1.8 g) are added and distillation is continued. The distillate is extracted with ether, and the extracts are washed with dilute hydrochloric acid until free from amine, neutralized with sodium hydrogen carbonate, and evaporated. The residue is mixed with 10% sodium hydroxide solution (10 ml) and distilled in steam. The bicyclo-[3.3.2]decan-3-ol that solidifies in the distillate is collected (7.5 g, 71 %). 

The introduction of alkali does, however, break up soluble iron aromatic compounds, such as hydroxylamine derivatives. Furthermore, it makes possible a more rapid distillation of the amine, as the introduction of the common ion OH reduces the solubility of aniline in water. In the preparation of water-soluble amines, neutralization of the charge is desirable only when the crude product is to be dehydrated and purified by distillation. The preparation of p-phenylenediamine is such an example. When the soluble amine is recovered by partial dehydration and crystallization, the faintly acid mother liquors, containing the active catalyst, can be used in subsequent reductions. 

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