Aromatic amines physical properties

Amine oxides, known as A[-oxides of tertiary amines, are classified as aromatic or aliphatic, depending on whether the nitrogen is part of an aromatic ring system or not. This stmctural difference accounts for the difference in chemical and physical properties between the two types. 

Aniline is an aromatic amine used in the manufacture of dyes, dye intermediates, rubber accelerators, and antioxidants. It has also been used as a solvent, in printing inks, and as an intermediate in the manufacture of pharmaceuticals, photographic developers, plastics, isocyanates, hydroquinones, herbicides, fungicides, and ion-exchange resins. It is produced commercially by catalytic vapor phase hydrogenation of nitrobenzene (Benya and Cornish 1994 HSDB 1996). Production of aniline oil was listed at approximately 1 billion pounds in 1993 (U.S. ITC 1994). Chemical and physical properties are listed in Table 1-2. 

Four types of organic amines exist, as shown in Table 4.8 primary amines RNHj, secondary R2NH2, tertiary RsNH, and quaternary R4N (Appendix D). The hydrocarbon chain R is usually of length Cg-Cu, commonly a straight aliphatic chain, but branched chains and aromatic parts also occur. In general the amines extract metal complexes in the order tertiary > secondary > primary. Only long-chain tertiary and—to a smaller extent—quarternary amines are used in industrial extraction, because of their suitable physical properties trioctylam-ine (TOA, 8 carbons per chain) and trilauryl amine (TLA, 12 carbons per chain) are the most frequently used. For simplicity we abbreviate all amines by RN, and their salts by RNH L . 

In particular, iminoboranes (XBNR) are isoelectronic with alkynes (XCCR). Well-known comparable pairs of isoelectronic species are aminoboranes (X2BNR2) and alkenes (X2CCR2), amine-boranes (X3BNR3) and alkanes (X3CCR3), borazines [(XBNR)3] and benzenes [(XCCR)3], etc. The structure of aminoboranes, amine-boranes, and borazines is well known from many examples. It has turned out that these BN species are not only isoelectronic, but also have structures comparable with the corresponding CC species. In the case of borazines, the aromatic character was widely discussed on the basis of theoretical and experimental arguments. The structural and physical properties of... 

Most local anesthetic agents consist of a lipophilic group (eg, an aromatic ring) connected by an intermediate chain via an ester or amide to an ionizable group (eg, a tertiary amine) (Table 26-1). In addition to the general physical properties of the molecules, specific stereochemical configurations are associated with differences in the potency of stereoisomers (eg, levobupivacaine, ropivacaine). Because ester links are more prone to hydrolysis than amide links, esters usually have a shorter duration of action. 

According to the submitters, other aromatic aldehydes and amines may be used in a similar manner with essentially the same yield of product. The exact procedure for isolation of the amine will depend upon its physical properties. Benzaldehyde and 0-toluidine yield o-tolylbenzylamine, m.p. 56-57° (hydrochloride, m.p. 165-166°), while />-tolylbenzylamine, obtained from />-toluidine, has a b.p. i62-i63°/5 mm. (hydrochloride, m.p. 181-182°). 

We have found similar results with other isocyanates, that is, they react with moisture to form the amines which react with isocyanates and build molecular weight. SFC provides a quick check on this process. Furthermore, films crosslinked with a virgin HDI and one crosslinked with an aged material will exhibit very different physical properties. This example shows the utility of SFC for aliphatic isocyanates, but aromatics isocyanates can also be characterized using SFC (2). 

Thermoset polyurethanes are cross-linked polymers, which are produced by casting or reaction injection molding (RIM). For cast elastomers, TDI in combination with 3,3,-dichloro-4,4,-diphen5lmethanediamine (MOCA) are often used. In the RIM technology, aromatic diamine chain extenders, such as diethyltoluenediamine (DETDA), are used to produce poly(urethane ureas) (47), and replacement of the polyether polyols with amine-terminated polyols produces polyureas (48). The aromatic diamines are soluble in the polyol and provide fast reaction rates. In 1985, internal mold release agents based on zinc stearate compatibilized with primary amines were introduced to the RIM process to minimize mold preparation and scrap from parts tom at demold. Some physical properties of RIM systems are listed in Table 7. 

The aromatic amine eutectics may crystallize on storage. They can be reliquefied by heating to 40°C with stirring. This liquefaction can be accomplished without sacrificing either the curing properties or the final physical and chemical properties of the cured resins. 

The most common cure conditions for the networks under consideration are Tcure < T and Tcure = const. Under these conditions, the most important feature of the thermosetting process is the vitrification of the reacting mixture which practically quenches chemical crosslinking (see Sect. 2) and changes the physical and mechanical properties of the reacting mixture. In this section, we shall mainly consider the properties of epoxy-aromatic amine glasses prepared at Tcure = 40-110 °C. 

Despite the many desirable properties of silica, its limited pH stability (between 2 and 7.5) is also a major issue in NPC when strong acidic or basic mobile-phase additives are used to minimize interactions. Hence, other inorganic materials such as alumina, titania, and zirconia, which not only have the desired physical properties of silica but also are stable over a wide pH range, have been studied. Recently, Unger and co-workers [22] have chosen a completely new approach where they use mesoporous particles based not only on silica but also on titania, alumina, zirconia, and alumosilicates. These materials have been used by the authors to analyze and separate different classes of aromatic amines, phenols, and PAHs (polyaromatic hydrocarbons). 

Various other condension products of dichloroethyl sulphide have been prepared, such as those with phenates, thiophenates, mercaptides and aromatic amines, and in every case the physical, chemical and biological properties of these have been studied. ... 

Melhylaminc nitrate Teiramcthylammonium nitrate Guanidine nitrate Nitrates of aromatic amines Ammonium chlorate Ammonium perchlorate Crystal structure and physical properties Thermal decomposition and burning of A P Thermal decomposition of irradiated ammonium perchlorate Influence of pressure on burning of A P Density and critical diameter... 

The production of coke by the carbonization of bituminous coal leads to the release of chemically complex emissions from coke ovens that include both gases and particulate matter of varying chemical composition. The chemical and physical properties of coke oven emissions vary depending on the constituents. The emissions include coal tar pitch volatiles (e.g., particulate polycyclic organic matter, polycyclic aromatic hydrocarbons, and polynuclear aromatic hydrocarbons), aromatic compounds (e.g., benzene and jS-naphthyl amine), trace metals (e.g., arsenic, beryllium, cadmium, chromium, lead, and nickel), and gases (e.g., nitric oxides and sulfur dioxide). 

Where the part to be molded is a large thin part (0.100") with a very long flow path for the entering reacting system, the very fast amine-extended systems are sometimes too fast, making it difficult to properly fill the mold. For such parts a modified aromatic amine-extended system has been developed which is an excellent compromise between physical properties... 

Aromatic amines. These include materials such as 4,4 -meth-ylenedianiline, m-phenylenediamine, and 4,4 -diamlnodiphenyl-sulfone. Aromatic amines are less reactive than aliphatic amines and usually require curing temperatures as high as 300 °F. Thus, they offer systems that have a long pot life at room temperature and cure to products with excellent physical and chemical property retention up to 300 F. 

PHYSICAL PROPERTIES Colorless solid used as yellow, tan or brown pellets faint amine-like odor soluble in hot methyl ethyl ketone, acetone, esters and aromatic hydrocarbons MP (99-107°C, 210-225°F) DN (1.44 g/mL at 25°C) VP (lE-05 mm Hg at 25°C). 

PHYSICAL PROPERTIES colorless, oily liquid aromatic amine-like odor burning taste soluble in water, alcohol, ether, and benzene miscible with chlorofom, carbon tetrachlo-... 

Louis P. Hammett (1894-1987) made two major contributions to physical-organic chemistry the first one (on which wc will focus) is the concept of supcracidity and his acidity function. The. second one is the so-called llammeti equation wiiich concents the correlation of equilibria and rales for reactions of substituted aromatic compounds. With A.H. Deynip. Hammett set up an acidity scale based on the indicator properties of aromatic amines, a. scale that measures 100% sulfuric acid as lo limes as strong as 10% acid, and then showed that this acidity scale was relevant to chemisir> ... 

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