Surfactants, Foam Control Additives

Surfactants are used, especially in water-based formulations, to improve wetting, dispersion, slip and mar properties and defoaming. The group includes ethoxylated products, acetylenic alcohols and diols and proprietary additives. 

Foaming can often be a serious problem in production and processing of polymer dispersions and latices, and silicone-based control systems have been developed to counter this effect. A range of products is available, giving choice of an appropriate grade to achieve high antifoam efficiency and/or high compatibility with specific products. 

Some foam control systems conform to the guidelines of the US Food and Drug Administration (FDA) and the German Health Office (EGA), for use in products, such as coated and printed packaging materials, which come into contact with foodstuffs. 

Two developments have been reported (by Wacker Chemie) supplementing its range of foam-control systems Silicone Antifoam Emulsions SE 84 and SE 85. Based on organically modified silicone fluids, they reduce or prevent flow defects in polymer films. 

Surfynol DF-62 is liquid 100% active ether-modified silicone defoamer, giving knockdown defoaming and long-term anti-foaming. 

---

The personal care industry remains traditionally the largest consumer of soaps depending on the region, from 50 to 75 % of the total surfactant consumption accounts for soaps [81], The increase in body shampoo consumption last decades is assumed to alter the soap market slightly. The consumption rate of soap in household and laundry aids is quite modest now and limited essentially by the "old times" detergents, foam-control additives, chlorine-containing alkali cleaners, and metal cutting oils. The sodium salts of rosin acids and wool wax acids are of some importance for technical needs and bar soaps. 

Recent research and field tests have focused on the use of relatively low concentrations or volumes of chemicals as additives to other oil recovery processes. Of particular interest is the use of surfactants as CO (184) and steam mobility control agents (foam). Also combinations of older EOR processes such as surfactant enhanced alkaline flooding and alkaline-surfactant-polymer flooding have been the subjects of recent interest. Older technologies polymer flooding (185,186) and micellar flooding (187-189) have been the subject of recent reviews. In 1988 84 commercial products polymers, surfactants, and other additives, were listed as being marketed by 19 companies for various enhanced oil recovery applications (190). 

Foam Control. Fermentations tend to froth because metabolites have surfactant properties. Prevention commonly is by addition of antifoam agents such as oils, heavy alcohols, fatty acids, or silicones. High-speed rotating impellers destroy bubbles by direct impact and by throwing them against the wall of the vessel. 

HERCULES 831 defoamer is a quick-dispersing, hydrocarbon oil-based antifoaming agent designed for use where immediate foam-control action is wanted. It is particularly suitable where addition adjacent to the foam-control point is required. Its efficiency is not adversely affected by temperature or pH, and it is effective in the presence of many surfactants. 

Figure 13.5 is an example of a collaborate activity of surfactant and filler in obtaining small and uniform cell sizes. The control foam was obtained with surfactant alone. The addition of silica increases nucleation and results in a very uniform polyurethane foam. This foam was developed to increase the insulation rating of refrigerator foams. ... 

Uses Synthetic fibers evaporation retardant on water surfaces surfactant for polymerization emollient in cosmetics foam control agent cosolvent plasticizer mfg. of household/industrial cleaners, personal care prods., textile auxs.. plasticizers, ore flotation, oil well drilling, metal lubricants, agric. additives raw material, consistency agent, emollient for pharmaceuticals as antihistamine in surf, lubricants for mfg. of food-contact metallic articles Regulatory EDA 21CER 178.3910... 

FIGURE 12.6. The microscxjpic anatomy of a foam. The complex interplay of interfacial and hydrauhc forces makes the understanding and control of foams a challenging proposition. The effective control of those interactions with surfactants or other additives determines the persistence of a given system. 

The performance of silicone-based antifoam compounds is independent of water hardness. They are effective at very low addition levels in all types of surfactant systems normally present in detergent formulations and across a wide range of use conditions. Furthermore, silicones cause no yellowing on fabric. Thus, silicone-based antifoam compounds have a number of benefits over soap-based foam control systems. 

An overview of lightweight drilling fluids is presented with a discussion of the application of foam as a drilling fluid. The primary classes of surfactants used in such fluids, of varying quality, are described. An overview of specialty surfa ant conditioning additives is presented. A novel foam control system is offered and several lightweight fluid case studies and field examples are showcased. 

There are also some additives used in formulating sizes. Fatty substances, e.g., ->fatty acid esters, in combination with nonionic or anionic emulsifiers (->surfactants), and - sulfonated oils plasticize the size film, impart antistatic properties, help in foam control and improve smoothness. Fatty alcohol ethoxylates are sometimes added to increase wettability of the yam. 

In addition to the mobihty control characteristics of surfactants, critical issues in gas mobihty control processes are surfactant salinity tolerance, hydrolytic stabihty under reservoir conditions, surfactant propagation through the reservoir, and foam stabihty in the presence of cmde oil saturations. 

Most thermoplastics and thermosets can be foamed, many of them into either flexible or rigid foams. The choice is controlled by the blowing agent, additives, surfactants, and mechanical handling. Some polymers can be expanded as much as 40 times their original density and still retain a substantial part of their strength. Most commercial foams are expanded to derisities of two to five pounds per cubic foot. (Water is 62 pounds per cubic foot.)... 

The term food colloids can be applied to all edible multi-phase systems such as foams, gels, dispersions and emulsions. Therefore, most manufactured foodstuffs can be classified as food colloids, and some natural ones also (notably milk). One of the key features of such systems is that they require the addition of a combination of surface-active molecules and thickeners for control of their texture and shelf-life. To achieve the requirements of consumers and food technologists, various combinations of proteins and polysaccharides are routinely used. The structures formed by these biopolymers in the bulk aqueous phase and at the surface of droplets and bubbles determine the long-term stability and rheological properties of food colloids. These structures are determined by the nature of the various kinds of biopolymer-biopolymer interactions, as well as by the interactions of the biopolymers with other food ingredients such as low-molecular-weight surfactants (emulsifiers). 

---