Quaternary amines alkyl quats

Quaternary ammonium compounds (quats) are prepared - by moderate heating of the amine and the alkyl halide in a suitable solvent - as the chlorides or the bromides. Subsequently conversion to the hydroxides may be carried out. Major applications of the quat chlorides are as fabric softeners and as starch cationizing agent. Several bio-active compounds (agrochemicals, pharmaceuticals) possess the quat-structure. Important applications of quat bromides are in phase transfer catalysis and in zeolite synthesis. 

Fig. 2.12.1. Chemical structure of different classes of cationic surfactants (a) quaternary ammonium surfactants (quats) (b) dialkylcarboxyethyl hydroxyethyl methyl ammonium surfactants (esterquats) (c) alkyl polyglycol amine surfactants (d) quaternary perfluoro-alkyl ammonium surfactants (e) N, N, N1, JV -tetramethyl-iV, iV -didodecyle-l,3-propane-diyle-diammonium dibromide (cationic gemini surfactant). R = alkyl or benzyl group.

Fatty acids are raw materials for fatty amines, ethoxylated fatty amines, quaternary ammonium compounds (Quats), fatty acid-polyamine condensates, fabric softeners based on esterquats, fatty add amides, alkyl keten dimers for paper sizing and amphoteric surfactants. Binding of oleic add anhydride to cellulose fibre by chemical grafting is a recently introduced sustainable process to protect construction timber for outdoor use, such as pinewood shutters, from moisture and outside attack. Impregnation of the wood involves two stages firstly in an autoclave, where vacuum and pressure ensure its penetration, and then in a tank where the wood is soaked in a bath of anhydride, to encourage grafting of the anhydride on the wood. ... 

Various classes of cationic surfactants, including quats, esterquats, alkyl ethoxy amines, quaternary perfluoroalkyl ammoniums and gemini surfactants have been analysed extensively with LC—MS and LC—MS—MS techniques, and their spectra have been fully characterised. Different ionisation methods have been applied for the detection of such surfactants, including API techniques (APCI and ESI) in negative and positive modes of operation. In addition, detailed examples regarding MS—MS fragmentation of these compounds have been reported and presented in this chapter. 

Two routes of catalyst decomposition are also possible from alkoxide 29, fragmentation to form an epoxide or O-alkylation and subsequent fragmentation to an enol ether. Both of these tertiary amines can then be IV-alkylated to form new chiral, non-racemic quat salts. The quaternary ammonium catalyst can also be dequatemarized by nucleophiles to a tertiary amine, which can then undergo subsequent reactions [9c, 1 li,26b,87]. 

Most unsaturated ring quats of industrial importance are alkylpyridinium halides (I) and substituted imidazolinium compounds (11). To prepare alkylpyridinium halide, pyridine is reacted with the equimolar amounts of alkyl halide for several hours at 100-150 °C without solvent according the reactions given above. The reaction is two orders slower in this case because the basicity of pyridine is much weaker in comparison with aliphatic tertiary amines and heterocyclic aliphatic amines, such as N-alkylpiperidine and N-alkylmorpholine, too. Typical examples of the aromatic quaternaries are given below ... 

By far the largest (46% of the total amine market) use of f was in fabric softeners ( quaternary ammonium compounds). Predominantly used were di-methyldialkylammonium chloride and the corresponding methyl sulfate. The alkyl is hydrogenated tallow. The volinne of f. in this area is reduced substantially since modem ester quats (->qtiatem-ary ammonium compounds) need no f Other quaternaries contain hydroxyethyl- or imidazolinium structures. Dispersions containing 5-7% f. are used in rinse cycles of household and commercial laundry machines, and 0.1-0.2% remains on the fabric. In drying cycles, the softeners are applied to the substrate (paper, wovens and nonwovens as well as foam pads). 

Dispersions of softeners, especially those of high concentration, often contain viscosity-reducing additives like fatty alcohols, amine ethoxylates, or acid ethoxylates. Instead of quaternary alkyl compounds, dialkyl imidazolinium compounds or ester quats are often used. Amidoamine quats like methyl-Z>/s(tallowamidoethyl)-2-hydroxyethyl ammonium methyl sulfate are also popular in North America. 

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