Amines triethylenetetramine

The most frequently registered allergens in hardeners were benzyl alcohol, tri(dimethylaminomethyl)phenol and several amines (triethylenetetramine, isophoronediamine, diethylenetriamine, tetraethylenepentamine). No specific changes in the registration were observed. 

Figure 5 illustrates the type of encapsulation process shown in Figure 4a when the core material is a water-immiscible Hquid. Reactant X, a multihmctional acid chloride, isocyanate, or combination of these reactants, is dissolved in the core material. The resulting mixture is emulsified in an aqueous phase that contains an emulsifier such as partially hydroly2ed poly(vinyl alcohol) or a lignosulfonate. Reactant Y, a multihmctional amine or combination of amines such as ethylenediamine, hexamethylenediamine, or triethylenetetramine, is added to the aqueous phase thereby initiating interfacial polymerisation and formation of a capsule shell. If reactant X is an acid chloride, base is added to the aqueous phase in order to act as an acid scavenger. 

Comparisons of the properties of solvent-free Hquid coatings based on unmodified bisphenol A epoxies cured with varying amine hardeners are shown in Table 6. Examples include diethylenetriamine [111-40-0] H2NC2H4NHC2H4NH2 (7), triethylenetetramine [112-24-3] ... 

Polyamides containing a-aminoacid units are readily obtained by reaction of bisazlactones (2-oxazolin-5-ones) with diamines. When polyamines such as diethylenetriamine (DETA) or triethylenetetramine (TETA) are used as the diamine component, the resultant polyamides readily cyclodehydrate above 200°C to produce polymers containing 2-imidazolin-5-one units in the backbone. Polyamides derived from simple diamines (e.g. 1,6-hexanedi amine) cyclodehydrate only in the presence of a suitable catalyst. Carboxylate salts and certain Lewis acids have been found to be efficient catalysts for this transformation. 

The presence of triethylenetetramine in the hydrothermal synthesis of open-framework zinc phosphates results in a number of frameworks with one- to three-dimensional structures. The structures include one-dimensional ladders, two-dimensional layer structures, and one structure where the tetramine is bound to the zinc center. The structural type was highly sensitive to the relative concentration of the amine and phosphoric acid.411 Piperazine and 2-methylpiperazine can be used as templating molecules in solvothermal syntheses of zinc phosphates. The crystallization processes of the zinc compounds were investigated by real time in situ measurements of synchrotron X-ray powder diffraction patterns.412... 

With the diglycidyl derivative of bisphenol A, aromatic amines such as 4,4 -methylene dianiline or diaminodiphenyl sulfone provide good thermal stability for the final cured resin. Although aliphatic primary amines react more rapidly (triethylenetetramine cures the above epoxy resin based on bisphenol A in 30 min at room temperature and causes it to exotherm up to 200°C), they are more difficult to handle and offer poor thermal stability. 

Tris-(2-aminoethyI)amine [4097-89-6] M 146.2, b 114 /15mm, 263 /744mm, d 0.977, n 1.498. For a separation from a mixture containing 62% TRIEN, see entry under triethylenetetramine. Also purified by conversion to the hydrochloride (see below), recrystn and regeneration of the free base [Xie and Hendrickson JACS 109 6981 1987]. 

Poly dentate amines, diethylenetriamine, triethylenetetramine and facultative ligands 721... 

In the first process EDC reacts with an excess of aqueous ammonia at about 180°C and 10 to 20 atmospheres. Diethylenetriamine and triethylenetetramine are also formed in secondary reactions of the ethylenediamine with EDC. Caustic is added to neutralize the crude product and free the ethylenediamine, the higher amines and the ammonia from the amine hydrochloride and ammonium chloride. The chloride salts are a waste that must be properly handled. The crude product is refined by fractionation. The unreacted ammonia is recycled, and the amines are purified. The yield of EDA is about 609c46. 

Abbreviations py = pyridine en = ethylenediamine Mejen = l r,i f-dimethyl-ethylenediamine EtenEt = JV,JV -diethylethylenediamine bipy = 2,2 -bipyridine Et4dien = JVfJV,JV, Ar,-tetraethyldiethylenetriamine 4,7-diphenylphen - 4,7-di-phenyl-l,10-phenanthroline tripyam = tri(2-pyridyl)amine (bidentate) dppa = phenyldi(2-pyridyl)amine trien — triethylenetetramine. 

In the case of PVA, while AG° varies continuously with a, AH0 remains constant in a large range of pH s (a = 0.5-0). This means that only the entropy term AS0 is responsible for the pK variation in the above range. A comparison with a simple tetraamine (triethylenetetramine) shows that all the thermodynamic values for PVA are similar to those obtained with simple low molecular weight amines. 

The chemical structures of important amines for curing epoxy resins in adhesive systems are identified in Fig. 5.1. Diethylenetriamine (DETA), triethylenetetramine (TETA), ra-aminoethylpiperazine (AEP), diethylaminopropylamine (DEAPA), ra-phenylenediamine (MPDA), and diaminodiphenyl sulfone (DDS) are the most commonly used members of this class. They are all primary amines. They give room or elevated temperature cure at near stoichiometric ratios. Ethylenediamine is too reactive to be used in most practical adhesive formulations. Polyoxypropyleneamines (amine-terminated polypropylene glycols) impart superior flexibility and adhesion. 

Table 11.8 presents a typical triethylenetetramine cured epoxy adhesive formulated with selected fillers. In this formulation the use of aluminum powder and alumina increases substantially the resistance of the adhesive to boiling water.7 This is also true when DETA is used as the curing agent.8 A typical room temperature cured aliphatic amine cured epoxy adhesive for general-purpose use is shown in Table 11.9. This shows the difference that is achieved in shear strength by curing at elevated temperatures versus room temperature.

From the above discussions it is clear that the amine has an important role in the formation of open-framework metal phosphates. Recent studies from this laboratory have shown that in the family of zinc phosphates, almost all the members in the hierarchy of open-framework structures can be synthesized using the same structure-directing agent, triethylenetetramine (TETA) [32], In Fig. 7.18 we show all the structures obtained with TETA along with the relative concentrations of the amine and the phosphoric acid employed in the synthesis. We see that the one-dimensional (ladder) and the two-dimensional (layer) structures are obtained when the relative concentration of phosphoric acid is high with the ratio of concentrations of the acid and the amine in the range 3 1-4 1. This is in contrast to the three-dimensional structures where the ratio... 

Iron(II) forms345 stable complexes with a range of polyethyleneamine and related polydentate amines. There has been considerable research effort346 devoted to the measurement of the thermodynamics of formation of these complexes in aqueous solution. Thus, for example, ethyl-enediamine347 forms mono, bis and tris complexes in aqueous media with successive enthalpies of reaction being 21,1,43.5 and 66.3 kJ mol-1 respectively. Similar thermochemical measurements have been made on a number of other polydentate amines, for example diethylenetriamine,348 2,2, 2"-tria-minotriethylamine,349 triethylenetetramine,350 tetraethylenepentamine351 and N,N,N, N -tetra(2-aminoethyl)ethylenediamine.352... 

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