Tertiary amines physical properties

Catalysis is usually accompHshed through the use of tertiary amines such as triethylenediamine. Other catalysts such as 2,4,6-/m(/V,/V-dimethylaminomethyl)phenol are used in the presence of high levels of cmde MDI to promote trimerization of the isocyanate and thus form isocyanurate ring stmctures. These groups are more thermally stable than the urethane stmcture and hence are desirable for improved flammabiUty resistance (236). Some urethane content is desirable for improved physical properties such as abrasion resistance. 

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. 

When additional substituents ate bonded to other ahcycHc carbons, geometric isomers result. Table 2 fists primary (1°), secondary (2°), and tertiary (3°) amine derivatives of cyclohexane and includes CAS Registry Numbers for cis and trans isomers of the 2-, 3-, and 4-methylcyclohexylamines in addition to identification of the isomer mixtures usually sold commercially. For the 1,2- and 1,3-isomers, the racemic mixture of optical isomers is specified ultimate identification by CAS Registry Number is fisted for the (+) and (—) enantiomers of /n t-2-methylcyclohexylamine. The 1,4-isomer has a plane of symmetry and hence no chiral centers and no stereoisomers. The methylcyclohexylamine geometric isomers have different physical properties and are interconvertible by dehydrogenation—hydrogenation through the imine. 

Amines are polar compounds. Primary and secondary amines can form hydrogen bonds, but tertiary amines cannot. Table 1.8 lists some common physical properties of amines. 

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 contrast, the micrographs of the ionomer pseudo-IPN coatings with opposite charge groups. Figure U- (A-2 to C-2), did not reveal any phase separation. No white particles of the VMCC phase were visible in the dark matrix of the PU phase. Presumably the ionic bonds between the carboxyl and tertiary amine groups provided the best opportunity for interpenetration between the linear chains of VMCC and the networks of PU to prevent any possible phase separation from the ionomer pseudo-IPN microphase. The physical properties of ionomer... 

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. 

Generally, when used as a sole catalyst, tertiary amines are used only in specialty applications where short pot life can be tolerated and where maximum physical or chemical properties are not required. DMP-10 and DMP-30 are used at concentrations of 4 to lOpph with liquid DGEBA epoxy resins. They achieve fairly fast cures overnight, even at room temperatures since the hydroxyl groups present in the epoxy molecule enhance the catalytic activity of the tertiary amine groups. 

The tertiary amine salts are claimed to provide epoxy formulations with very good adhesion to metal. The cured resins also show a hydrophobic effect when in contact with water or at high humidities. The strength, toughness, and elongation (4.7 percent) of the cured epoxy resin are very good. However, heat distortion temperature is only in the range of 70 to 80°C, and chemical resistance is relatively poor for an epoxy. The physical properties fall off rapidly with any rise in temperature. 

Epoxy-polysulfide systems can be formulated either as a liquid DGEBA epoxy mixed with liquid poly sulfide polymer or as an epoxy-terminated polysulfide polymer either may be cured with a tertiary amine such as DMP-30. Table 11.19 describes the formulation and shows the physical properties of these epoxy-polysulfide adhesives compared to an unmodified epoxy adhesive. 

Nitrogen mustards are tertiary hw(2-chloroethyl)amines with vesicant activity (NDRC, 1946). AH are active alkylating agents. The nomenclature, chemical and physical properties of HNl, HN2, and HN3 are summarized in Tables 8.3 and 8.4. Due to their toxicity and various... 

The existence of such an inner salt is well established by the physical properties of many amino acids and by the chemical reactions of the higher alkylated amino derivatives formed by converting the primary amine group into secondary and tertiary alkyl amine groups. 

The reaction between an isocyanate and the hydroxyl group in a polyol will take place without a catalyst, but at too slow a rate to be practical. Without a catalyst a foam may expand, but it may not cure adequately to give good physical properties. The urethane reaction can be catalyzed by basic materials such as the tertiary amines (20). 

A.16.3 The major difference is the functional group attached to the oxygen on the phosphorous atom. PA has an H attached to it. PE has two carbons and a primary amine, while PC has two carbons and a tertiary amine with three methyl groups. This changes the relative volume of the headgroups which has a substantial impact on the physical properties of the lipids. 

Saturated heterocycles containing five or more atoms have physical and chemical properties typical of acyclic compounds that contain the same heteroatom. For example, pyrrolidine, piperidine, and morpholine are typical secondary amines, and A-methylpyrrolidine and quinuclidine are typical tertiary amines. The conjugate acids of these amines have pK values expected for ammonium ions. We have seen that the basicity of amines allows them to be easily separated from other organic compounds (Chapter 1, Problems 70 and 71). 

Tetraalkylammonium salts, first synthesized by Hofmann in 1851 by the reaction of a tertiary amine with an alkyl halide, are soluble in various polar solvents. These salts form crystalline hydrates that contain large numbers of water of hydration molecules. The unusual physical properties of tetraalkylammonium salts and their effects on the structure of bulk water have been reported.2 3,4,5 currently, several theories exist as to the effects of the tetraalkylammonium cations on the structure or entropy of bulk water. Yet to be understood are the effects of the anions associated with the tetraalkylammonium ions on the overall structure of water. Not only Is the theory of interactions of such salts with water of interest to those engaged in basic chemistry, but the salts also are used in various applications. 

Polyalkylenimines (PAIs) are a class of cationic polymers that have a generalised structure with secondary or tertiary amines in the main separated by all lene spacers, as shown in Scheme 2.1. Due to the presence of the nucleophilic amine groups in the polymer backbone, their synthesis is more complicated compared to simpler vinyl based polymers. This chapter will focus on the synthesis of the PAIs, their physical properties and a short review of applications, focusing on gene delivery. This chapter will only cover PAI homopolymers and excludes the convoluted area of block copolymers, as this is worth a full review by itself. 

Alkylamido betaines are usually supplied as 30% aqueous solutions, containing several by-products, which may effect the physical properties or the toxicological profile of the betaine. Formerly, CAPB contained approximately 3% of the amidoamine because of an incomplete reaction. The amidoamine has some advantages, contributing to viscosity and providing some sub-stantivity to hair and skin. The tertiary amine is an irritant and sensitization is suspected to be related to the level of the tertiary amine (10) or the dimethyl aminoamine (11). The content of amidoamine in modem... 

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