Industrial quaternary ammonium compounds

TABLE 4. Examples of environmental, occupational and quality control protocols for industrial quaternary ammonium compounds... 

The threat of accidental misuse of quaternary ammonium compounds coupled with potential harmful effects to sensitive species of fish and invertebrates has prompted some concern. Industry has responded with an effort to replace the questionable compounds with those of a more environmentally friendly nature. Newer classes of quaternaries, eg, esters (206) and betaine esters (207), have been developed. These materials are more readily biodegraded. The mechanisms of antimicrobial activity and hydrolysis of these compounds have been studied (207). AppHcations as surface disinfectants, antimicrobials, and in vitro microbiocidals have also been reported. Examples of ester-type quaternaries are shown in Figure 1. 

Uses of quaternary ammonium compounds range from surfactants to germicides and encompass a number of diverse industries (see Table 1). 

Nearly all uses and appHcations of benzyl chloride are related to reactions of the active haUde substituent. More than two-thirds of benzyl chloride produced is used in the manufacture of benzyl butyl-phthalate, a plasticizer used extensively in vinyl flooring and other flexible poly(vinyl chloride) uses such as food packaging. Other significant uses are the manufacture of benzyl alcohol [100-51-6] and of benzyl chloride-derived quaternary ammonium compounds, each of which consumes more than 10% of the benzyl chloride produced. Smaller volume uses include the manufacture of benzyl cyanide [140-29-4], benzyl esters such as benzyl acetate [140-11-4], butyrate, cinnamate, and saUcylate, benzylamine [100-46-9], and benzyl dimethyl amine [103-83-8], and -benzylphenol [101-53-1]. In the dye industry benzyl chloride is used as an intermediate in the manufacture of triphenylmethane dyes (qv). First generation derivatives of benzyl chloride are processed further to pharmaceutical, perfume, and flavor products. 

There are a number of industrially important reactions where two liquid phases are involved and the aqueous phase contains ionic species. Here the rate may be severely limited due to low solubiblity of the reactant, located in the organic phase, in water. We would benefit from using a pha.se-transfer (PT) catalyst, which ferries the ionic species into the organic phase thus overcoming a severe limitation. Such PT catalysts are typically quaternary ammonium compounds like tetrabutylammonium halides, trioctylmethylammonium chloride, etc. (see also Section 3.8). 

The simultaneous ionic and covalent character of quaternary ammonium compounds (197a) is central to most of their applications. TV-Quatemized heteroaromatic compounds possess many of the properties of 197a, and will be mentioned occasionaly in this chapter. In Table 4 are listed some quaternary ammonium compounds that have found industrial application. Many analytical methods make use of this class of compounds both as essential reagents or as accessories however, in the present chapter quaternary ammonium compounds will appear only as analytes. 

The quaternary ammonium compounds (23) and (24) are most often used as disinfectants and sanitizers for hard surfaces. Other industrial applications are limited to slimicides for paper mills and cooling-water systems. 

Antiseptics - [DISINFECTANTS AND ANTISEPTICS] (Vol 8) -industrial applications [INDUSTRIAL ANTIMICROBIAL AGENTS] (Vol 14) -mercury compounds in [MERCURY COMPOUNDS] (Vol 16) -mercury-containing [MERCURY] (Vol 16) -quaternary ammonium compounds as [QUATERNARY AMMONIUM COMPOUNDS] (Vol 20)... 

Schomacker compared the use of nonionic microemulsions with phase transfer catalysis for several different types of organic reactions and concluded that the former was more laborious since the pseudo-ternary phase diagram of the system had to be determined and the reaction temperature needed to be carefully monitored [13,29]. The main advantage of the microemulsion route for industrial use is related to the ecotoxicity of the effluent. Whereas nonionic surfactants are considered relatively harmless, quaternary ammonium compounds exhibit considerable fish toxicity. 

Methyl chloride is the only chlorinated methane with good growth. The principal use for methyl chloride is in the manufacture of chlorosilanes (89%) for the silicone industry. Other smaller uses are for methyl cellulose ether, quaternary ammonium compounds, herbicides, and butyl rubber. 

SPILL CLEAN-UP use water spray to "knock down" dust use solvent extraction with high molecular-weight amines and quaternary ammonium compounds for the removal or arsenic from industrial effluents. 

Fig. 15.7 One of the first published ion chro- of quaternary ammonium compounds. Repro matography application interfaced by ESI with duced with permission from [473] American MS. ESI-IC-MS(+) total ion current trace (TIC) Chemical Society 1990. and selected mass traces of an industrial blend...

The common chemical classes of antimicrobial agents used in industry are phenolics, halogen compounds, quaternary ammonium compounds, metal derivatives, amines, alkanol amines, nitro derivatives, anilides, organo-sulfur and sulfur nitrogen compounds. Some recommended agents for latex use are pentachlorophenol, tetrachloroisophthalonitrile, o-phenylphenol, tributyltin oxide, 2-n-octyl-4-isothiazolin-3-one, l-(3-chloroallyl)-3,5,7-tri-aza-l-azoniaadamantane chloride [119],... 

Quaternary ammonium compounds play a vital role in the formulation of hair and skin care products, and for use in the personal care industry can be divided into three categories, i.e. (i) alkyl quaternary ammonium compounds (including mono-, di- and trialkyl quaternaries), (ii) ethoxylated quaternaries, and (iii) ester quaternaries. The synthetic route for preparing such compounds is shown in Figure 14.24. 

During the last decade, the dialkylester quats have to a large extent replaced the stable dialkyl quats as rinse-cycle softeners, which is the single largest application for quaternary ammonium compounds. The switch from stable dialkyl quats to dialkylester quats may represent the most dramatic change of product type in the history of surfactants, and is entirely environment-driven. Unlike stable quats, ester quats show excellent values for biodegradability and aquatic toxicity. Ester quats have also fully or partially replaced traditional quats in other applications of cationics, such as hair care products and various industrial formulations. 

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