Detergents synthetic

Detergents are substances including soaps that cleanse by micellar action A large number of synthetic detergents are known One example is sodium lauryl sulfate Sodium lauryl sulfate has a long hydrocarbon chain terminating m a polar sulfate ion and forms soap like micelles m water... 

Synthetic Detergents. Examples of shampoo formulations are given in Table 1. The names of the ingredients are those designated by the Cosmetics, Toiletry and Fragrance Association (CTFA). 

A.gllsethionates. These are among the oldest of the synthetic detergents and were developed ia Germany to overcome problems of hard water. They are prepared by reaction of fatty acid chlorides with a salt of isethionic acid, ie, 2-hydroxyethanesulfonic acid [107-36-8]. These detergents have moderate foaming properties and have seen only limited use ia shampoos. 

The synthetic detergent industry has become one of the largest chemical process industries (see Detergency). Sales in 1989 were estimated at more than 4 biUion in the United States alone. As of 1989, the worldwide aimual production of linear a1ky1hen2ene (LAB) and branched a1ky1hen2ene (DDE) was estimated to be about 1.8 million tons and 230,000 tons, respectively (71,72). 

Detergents. The most widely used surfactant in synthetic detergents is the readily biodegradable linear alkyl sulfonate (LAS). Since the... 

Pipes, valves, fittings, and almost all other components of small equipment are now available in plastic or ceramics, which do not corrode in salt water and are less expensive than the metals now used. Synthetic detergents are now available for use with seawater, although a final rinse with freshwater may be desired. Saltwater sewage can be treated successfully. Dual water systems using freshwater and seawater are already in use on ships and in many island resort hotels. Many of these also have seawater systems for fire fighting. This trend will grow. 

Chlorosulfuric acid attacks brass, bronze, lead, and most other nonferrous metals. From a corrosion standpoint, carbon steel and cast Hon are acceptable below 35°C provided color and Hon content is not a concern. Stainless steels (300-series) and certain aluminum alloys are acceptable materials of constmction, as is HasteUoy. Glass, glass-lined steel, or Teflon-lined piping and equipment are the preferred materials at elevated temperatures and/or high velocities or where trace Hon contamination is a problem, such as in the synthetic detergent industry. 

The solubihty characteristics of sodium acyl isethionates allow them to be used in synthetic detergent (syndet) bars. Complex blends of an isethionate and various soaps, free fatty acids, and small amounts of other surfactants reportedly are essentially nonirritant skin cleansers (66). As a rule, the more detersive surfactants, for example alkyl sulfates, a-olefin sulfonates, and alkylaryl sulfonates, are used in limited amounts in skin cleansers. Most skin cleansers are compounded to leave an emollient residue on the skin after rinsing with water. Free fatty acids, alkyl betaines, and some compatible cationic or quaternary compounds have been found to be especially useful. A mildly acidic environment on the skin helps control the growth of resident microbial species. Detergent-based skin cleansers can be formulated with abrasives to remove scaly or hard-to-remove materials from the skin. 

One principal use of cyclohexanol has been in the manufacture of esters for use as plasticizers (qv), ie, cyclohexyl and dicyclohexyl phthalates. In the finishes industry, cyclohexanol is used as a solvent for lacquers, shellacs, and varnishes. Its low volatiUty helps to improve secondary flow and to prevent blushing. It also improves the miscibility of cellulose nitrate and resin solutions and helps maintain homogeneity during drying of lacquers. Reaction of cyclohexanol with ammonia produces cyclohexylamine [108-91-8], a corrosion inhibitor. Cyclohexanol is used as a stabilizer and homogenizer for soaps and synthetic detergent emulsions. It is used also by the textile industry as a dye solvent and kier-boiling assistant (see Dye carriers). 

Scouring may be conducted on jigs, boil-off machines, or kettles, depending on fabric weight, constmction, and crease tendency ia the rope form. A combination of a synthetic detergent and soda ash is usually used and scouring is conducted at 85—100°C. Certain nylon blends may require less stringent conditions and the use of less alkaline builders, such as tetrasodium pyrophosphate. 

Elastomeric Fibers. Elastomeric fibers are polyurethanes combiaed with other nonelastic fibers to produce fabrics with controlled elasticity (see Fibers, elastomeric). Processing chemicals must be carefully selected to protect all fibers present ia the blend. Prior to scouriag, the fabrics are normally steamed to relax uneven tensions placed on the fibers duriag weaving. Scouriag, which is used to remove lubricants and siting, is normally conducted with aqueous solutions of synthetic detergents and tetrasodium pyrophosphate, with aqueous emulsions of perchloroethylene or with mineral spidts and sodium pyrophosphate. 

Detergents are designed to be effective in hard water, meaning water containing calcium salts that fonn insoluble calcium caiboxylates with soaps. These precipitates rob the soap of its cleansing power and fonn an unpleasant scum. The calcium salts of synthetic detergents such as sodium lauryl sulfate, however, are soluble and retain then- micelle-fonning ability even in hard water. 

Detergents (Section 19.5) Substances that clean by micellar action. Although the term usually refers to a synthetic detergent, soaps are also detergents. 

Normal paraffins in this range are important intermediates for alkylating benzene for synthetic detergents production (Chapter 10). They are also good feedstocks for single-cell protein (SCP). 

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