Monoethylamine

Monoethylamine is a water-white liquid which is commercially ovailable as a 70% aqueous solution. It is soluble in ethyl alcohol/ methyl alcohol/ the paraffin hydrocarbons, aromatic ond aliphatic hydrocarbons, ethyl ether, ethyl acetate, acetone, fixed oils, mineral oil, oleic and stearic ocids. It is also soluble in hot paraffin and carnauba waxes, which solidify when cooled. 

Boiling point Critical denuty Critical pressure Critical temperature Dissociation coostanl Flash point (open cup) 

Heat of Vaporization at 58 C Heat of solution in water at room temperature Melting pmnt Specific gravity at 20/20 C 

Specific heat of liquid at 22.8 0 Refractive Index at 17.8 C Viscosity at 25 C Weight per gallon (20 C) Distillation range Initial boiling point Final boiling point Purity 

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Ethylamine, monoethylamine, CH3CH2NH2-B.p. 19 C. Prepared by reduction of acetonitrile or by heating ethyl chloride with alcoholic ammonia under pressure. It is a strong base and will displace ammonia from ammonium salts. Forms a crystalline hydrochloride and also crystalline compounds with various metallic chlorides. 

Complexes of boron trifluoride and amines such as monoethylamine are of interest because of the very long pot lives possible. The disadvantages of these complexes are their hygroscopic nature and the corrosive effects of BF3 liberated during cure. 

Chemical Designations - Synonyms Aminoethane, Monoethylamine Chemical Formula C HjNHj. Ohservahle Characteristics - Physical State (as normally shipped) Liquid Color Colorless Odor Pungent strong ammoniacal. 

Monoethylamine is used in the synthesis of Sevin, an important insecticide. Trimethylamine has only one major use, the synthesis of choline, a high-energy additive for poultry feed. 

It was later shown that aziridine reacts over mixtures of zinc and chromium oxides on alumina at 400°C to give the same products as those obtained from mixtures of NH3 and acetylene [221]. Aziridine, which would form by addition of NH3 to acetylene followed by IH (Scheme 4-8), was thus postulated to be an intermediate in the formation of acetonitrile (by dehydrogenation), monoethylamine (by hydrogenation) and all other heterocyclic bases (by ammonolysis and subsequent reactions) [221]. 

Synonyms AI3-24228 Aminoethane 1-Aminoethane BRN 0505933 CCRIS 6261 EINECS 200-834-7 Ethanamine Monoethylamine UN 1036. 

Being an electron deficient compound, boron trifluoride forms complexes with Lewis bases and compounds that have unshared pair(s) of electrons. With ammonia, it forms boron trifluoride ammonia. Similar coordination compounds are formed with monoethylamine, BF3-NH2C2H5 diethyl ether, CH3CH20(BF3)CH2CH3 and methanol, BF3—OHCH3. It forms a sohd complex HNO3-2BF3 with concentrated nitric acid. 

The two most common BF3 amine catalysts used commercially to cure epoxies are boron trifluoride monoethylamine, BF3 NH2C2H5, and boron trifluoride piperidine, BF3 NHCsHi0, complexes. Such complexes are latent catalysts at room temperature but enhance epoxide group reactivity at higher temperatures. 

In this Sect, we report systematic DSC studies of (i) the constituents of boron tri-fluoride monoethylamine (BF3 NH2C2H5) catalyzed TGDDM-DDS epoxies and their mixtures (ii) the nature of the catalyzed cure reactions and (iii) the environmental sensitivity of the BF3 NH2CzH5 catalyst. DSC studies are also reported on the cure reaction characteristics and environmental sensitivity of commercial prepregs that contain BF3 amine catalysts. 

The rate of stripping or the stripability on catalyzed urethane and epoxy resin finishes can be increased by adding formic acid, acetic acid, and phenol. Sodium hydroxide, potassium hydroxide, and tnsodium phosphate may be added to the formula to increase the stripability on enamel and latex paints. Other activators include oleic acid, trichloroacetic acid, ammonia, triethanolamine, and monoethylamine. Methylene chloride-type removers arc unique in their ability to accept cosolvcnts and activators that allow the soludon to be neutral, alkaline, or acidic. This ability greatly expands the number of coalings that can be removed with methylene chloride removers. 

Most studies of proton transfer in aromatic molecules concern phenol (Abe et al. 1982a,b,c Fuke and Kaya 1983 Gonohe et al. 1985 Jouvet et al. 1990 Lipert and Colson 1988 Mikami et al. 1987, 1988 Oikawa et al. 1983 Solgadi et al 1988 Steadman and Syage 1990 Syage 1990 Syage and Steadman 1991) or 1-naphthol (Cheshnovsky and Leutwyler 1985, 1988 Knochenmuss et al. 1988 Knochenmuss and Leutwyler 1989). These compounds can be associated with various proton acceptors ammonia, water, methanol, monoethylamine, piperidine, etc., differing essentially by their different gas phase proton affinities. 

Figure 4-13. Fluorescence spectra of phenol(MEA) clusters (MEA = monoethylamine). The spectra of the clusters (full line) were obtained by measurement of the fluorescence cut by a series of filters, (a) Fluorescence of phenol(MEA) with n <2 (excitation wavelength 280.9 nm). For comparison, the fluorescence spectrum in a solution of phenol in ethanol (excitation wavelength = 280 nm) is represented by a dashed line, (b) Fluorescence spectrum for a larger phenol(MEA) clusters (excitation wavelength = 281.5 nm). The fluorescence spectrum in a solution of phenolate anion in NaOH 10-4 mol P1 in ethanol is represented by a dashed line. The maxima of these curves have been normalized to unity. The mass spectra of the clusters corresponding to these excitation conditions are given in the lower part of the figure.

How can the size dependent reactivity be rationalized and what are the important factors which are responsible for this cluster size reactivity Experiments have been performed with 1-naphthol associated with other molecules (Knochenmuss et al. 1988 Knochenmuss and Leutwyler 1989). Naphthol undergoes proton transfer with two molecules of piperidine. For phenol, one needs three of four ammonia or three monoethylamine (MEA) molecules for the same process. 

Figure 4-17. Relation between gas phase proton affinities (in kcal mol-1) of base molecules B or B clusters and spectral shifts of the S3 <- S0 state of phenol(B ) and naphthol(B ) (Cheshnovsky and Leutwyler 1988) clusters (in cm-1). (A) water ( + ) (NH3) (x) monoethylamine (O) diethylamine ( ) trimethylamine.

For the stronger proton acceptors (ammonia, monoethylamine, and piperidine) a relation between the B proton affinities and the spectral shifts of the S3 <- S0 states of phenol(B) or naphthol(B) shows a linear dependence for proton affinities lower than a limit value situated around 10.4 eV (s240 kcal mol-1) for both phenol or naphthol molecules. Above this limit, the spectral shift is much larger and is different for phenol and 1-naphthol (see Figure 4-17). Nevetheless, this limit seems to correspond with the energetical limit of the proton transfer reaction. 

Boron trifluoride monoethylamine (BF3-MEA) is a Lewis acid catalyst. Lewis acids are electron pair acceptors that function as curing agents by coordinating with the epoxy oxygen,... 

Although it is formed from a very reactive catalyst (BF3 gas), the monoethylamine blocks the reactions sufficiently that BF3-MEA can be considered to be a latent catalyst. It provides a pot life of 6 to 12 months at room temperature. It does not show significant curing activity until temperatures of 100 to 125°C have been reached. 

It easily forms double compds, such as boron trifluoride etherate. Another compd, boron trifluoride-monoethylamine, BF3— C2H5NH2 is wh to pale tan flakes, melting at 88—90°. It released BF3 above 110° and is used for elevated temp cure of epoxy resins Refs 1) Gmelin-Kraut Syst Number 13(1954), 168 2) CondChemDict (1961), 166-tL R ... 

SYNS AETHYLAMINE (GERMAN) AMINOETHANE 1-AMINOETPiANE ETHANAiMINE ETHYLAMINE (UN 1036) (DOT) ETHYLAMINE, aqueous solution with not <50% but not >70% ethylamine (UN 2270) (DOT) ETILAMINA (ITALIAN) ETYLOAMINA (POLISH) MONOETHYL MINE (DOT) MONOETHYLAMINE, anhydrous (DOT)... 

Comments eglumine is prepared similarly to meglumine except that monoethylamine is used as the precursor, instead of monomethylamine. 

Book describes a mixer-heat exchanger section of a monoethylamine plant that is illustrated in Fig. P5.10 along with the notation. Trimethylamine recycle enters in stream 4, is cooled in the heat exchanger, and is mixed with water from stream 1 in mixer 1, The trimethylamine-water mixture is used as the cold-side fluid in the heat exchanger and is then mixed with the ammonia-methanol stream from the gas absorber in mixer 3. The mixture leaving mixer 3 is the reaction mixture which feeds into the preheater of the existing plant. 

Synonyms Ethanamine Monoethylamine Ami-noethane 1-Aminoethane Chemical/Pharmaceutical/Other Class Amine Chemical Formula C2H7N Chemical Structure C2H5NH2... 

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