Surfactant applications Leather

Together, antifreeze, PET, and polyester polymers account for about 98% of the ethylene glycol produced in the United States. It is also used sometimes as a deicer for aircraft surfaces. The two hydroxyl groups in the EG molecule also make EG suitable for the manufacture of surfactants and in latex paints. Other applications include hydraulic brake fluid, the manufacture of alkyd resins for surface coatings, and stabilizers for water dispersions of urea-formaldehyde and melamine-formaldehyde The hygroscopic properties (absorbs moisture from the air) make EG useful as a humectant for textile fibers, paper, leather, and adhesives treatment. 

MIBK is a highly effective separating agent for metals from solutions of their salts and is used in the mining industries to extract plutonium from uranium, niobium from tantalum, and zirconium from hafnium (112,113). MIBK is also used in the production of specialty surfactants for inks (qv), paints, and pesticide formulations, examples of which are 2,4,7,9-tetramethyl-5-decyn-4,7-diol and its ethoxylated adduct. Other applications include as a solvent for adhesives and wax/oil separation (114), in leather (qv) finishing, textile coating, and as a denaturant for ethanol formulations. 

Aqueous dispersions of poly(vinyl acetate) and vinyl acetate-ethylene copolymers, homo- and copolymers of acrylic monomers, and styrene-butadiene copolymers are the most important types of polymer latexes today. Applications include paints, coatings, adhesives, paper manufacturing, leather manufacturing, textiles and other industries. In addition to emulsion polymerization, other aqueous free-radical polymerizations are applied on a large scale. In suspension polymerization a water-irnrniscible olefinic monomer is also polymerized. However, by contrast to emulsion polymerization a monomer-soluble initiator is employed, and usually no surfactant is added. Polymerization occurs in the monomer droplets, with kinetics similar to bulk polymerization. The particles obtained are much larger (>15 pm) than in emulsion polymerization, and they do not form stable latexes but precipitate during polymerization (Scheme 7.2). 

The large-scale application of micro emulsions in leather degreasing was motivated by questioning current industrial processes for degreasing due to potentially environmental concerns. Of relevance for leather degreasing were mainly two processes, a solvent-based one and a water-based one. The surfactants showing the best performance in the latter... 

The use of amphoteric surfactants in heavy industry is a broad topic encompassing such varied applications as oil well and mining fluids, fire fighting foams, printing inks, wastewater effluent recovery aids, leather softeners, electroplating bath additives and corrosion inhibitors (120-129). While these topics are beyond the scope of this present chapter, they are worth mentioning since developments involving amphoteric surfactants here will ultimately have an impact on their consumption and availability in consumer markets and elsewhere. 

While the largest and most obvious use of surfactants is in formulated detergents, there are many other applications, some of which will be discussed in later parts of this chapter. Surfactants are used in many chemical processes, notably in waterborne polymerization processes (3), textile manufacture, flow and leveling of coatings, and leather processing. They are also used in metal working and in lubricants notably, in formulated automotive lubricants and oil. 

The first well-documented synthetic (nonsoap) materials employed specifically for their surface-active properties were the sulfated oils. Sulfonated castor oil, produced by the action of sulfuric acid on the castor oil, was originally known as turkey red oU. It was introduced in the late nineteenth century as a dyeing aid and is still used in the textile and leather industries today. The first surfactants for general application that have been traditionally classified as synthetic were developed in Germany during World War I in an attempt to overcome shortages of available animal and vegetable fats. Those materials were short-chain alkyl-naphthalene sulfonates prepared by the reaction of propyl or butyl alcohol with... 

---