Quaternary amines amine value

There are no universally accepted wet analytical methods for the characteri2ation of quaternary ammonium compounds. The American Oil Chemists Society (AOCS) has estabhshed, however, a number of appHcable tests (180). These include sampling, color, moisture, amine value, ash, iodine value, average molecular weight, pH, and flash point. 

Reaction selectivity of the parent ortho-QM has also been explored with a variety of amino acid and related species.30 In these examples, the rates of alkylation and adduct yields were quantified over a range of temperatures and pH values. The initial QM3 was generated by exposing a quaternary benzyl amine (QMP3) to heat or ultraviolet radiation (Scheme 9.10). Reversible generation of QM3 was implied by subsequent exchange of nucleophiles at the benzylic position under alternative photochemical or thermal activation.30 Report of this work also included the first suggestion that the reversible nature of QM alkylation could be used for controlled delivery of a potent electrophile. 

Molybdenum can also be recovered economically from some uranium leach liquors, particularly those of the USA. When uranium is stripped from amine extractants by solutions of sodium chloride, any molybdenum present remains in the organic phase, and can be subsequently recovered by being stripped into a solution of sodium carbonate. A process has been operated in which the strip liquor is acidified to a pH value of 4.5 and the molybdenum is reextracted into a solution of quaternary amine chloride in kerosene.218 The extracted metal is stripped into a solution containing sodium hydroxide and sodium chloride to produce liquors containing 30-40 g of molybdenum per litre, from which calcium molybdate can be precipitated by the addition of calcium chloride. 

The great majority of alkaloids, local anaesthetics, barbiturates, and neuroleptics have values between 6 and 8, so that both ionic and neutral species are present, in equilibrium, at physiological pH values. These substances will be considered in Sections 10.4 and 10.5. Among the alkaloids, atropine (piQ 10) (7.16) and tubocurarine (2.6) are atypical in having a higher degree of ionization. Tubocurarine is a quaternary amine and hence completely ionized at all pH values. Other quaternary amines used in medicine are ... 

Homopolymers, as well as random and block copolymers with PDMS, were created by a combination of polycondensation and anionic ring-opening polymerization. To convert the chlor-opropyl side groups into quaternary ammoniums, the polymer was first treated with lithium bromide to replace the chlorine with bromine. The polymer was dissolved with (3-hydroxypro-pyl)dimethylamine to create the amphiphilic quaternary amine-functionalized polymer. Bactericidal assays of statistical and block copolymers gave MIC values of 6-25 pgmr against E. coli and S. aureus, with somewhat better activity against S. aureus. 

D 2076-64 (Reapproved 1987) Acid Value and Amine Value of Fatty Quaternary Ammonium Chlorides D 2078-86 Iodine Value of Fatty Quaternary Ammonium Chlorides D 2080-64 Average Molecular Weight of Fatty Quaternary Ammonium Chlorides... 

The main types of cationic surfactants of pharmaceutical importance have hydrocarbon chains containing between 8 and 18 carbon atoms to which are attached amine, pyridinium or piperidinium groups. There is an important difference between the effect of pH on the properties of the primary, secondary and tertiary amines and on those of the quaternary amines. Whilst the quaternary amines are ionized at all pH values, the other classes of amine are fully charged... 

Quaternary amines are charged at all pH values and behave rather like inorganic ions and they are thus able to bind to negatively charged groups on proteins. 

The significance of amine value varies with the product. The procedure below, based on simple titration to a visual end point, is useful for quality control of a well-characterized material. For quaternaries, a high amine value may indicate that the compound is not completely neutralized, or it may indicate that primary, secondary, or tertiary amine is present. For new products, it is preferable to conduct the analysis with a recording potentiometric titrator. In the case of a quaternary amine hydroxide, two inflections may be observed. The first is due to the strongly basic quaternary, the second to more weakly basic amines. 

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