Foam volume solubility

C. Among sodium salts, hexadecyl sulfate gave a maximum foam volume, above 700 cm3, at 75 °C while at 50°C the maximum corresponds to tetradecyl sulfate but, as expected, with a lower volume (around 550 cm3). The fact that solubility in water decreases as the chain length increases can explain the progressive displacement of the maximum to higher homologs as the temperature increases. 

Limited digestion of globular soy proteins with rennin affords a modified protein preparation which retains a high molecular weight (47). Whipping quality, measured by foam volume and stability, was superior in comparison with native proteins. The limited rennin proteolysis of soy was identified as a key factor in functionality, since this modification conferred improved solubility. 

At pH 6.7 and 8.2, the smallest Increases In foam volume due to whipping occurred (Figure 7). Percentage of protein In the soluble fraction of the pH 6.7 suspension was highly variable (Figure 5). Foam volume Improved as salt concentration increased at this pH. Changing the pH from 6.7 to 4.0 to 6.7 improved the volume of foam formed over that of the unadjusted (pH 6.7) suspension, despite variation In percentage of protein In the soluble fractions. 

Whether obtained by one- or two-step pH adjustment, at pH 8.2 the percentages of protein in soluble extracts were among the the highest observed In the study, yet Increases In foam volume were not as great as those observed at pH 1.5 or 4.0. 

The foaming capacity of succinylated soy protein was significantly better than those of the unmodifided proteins. Foam volumes progressively increased with pH from 3 to 10 (12). Succi-nylation caused a small increase in foaming capacity of cottonseed flour (38). Solubility is required for the production of protein foams (48), and succinylation substantially increased the foaming ability of soy isolate by enhancing their solubility. 

Several recent patents describe the benefits of polymers in LDLDs (Table 7.15). Polymers are well known to interact with surfactants and provide many interesting properties. Some of the benefits claimed in the patents summarized in Table 7.15 are soil resistance due to amino acid copolymers, polyethylene glycol as a grease release agent, increased grease removal from polyoxyethylene diamine, enhanced foam volume and duration, increased solubility, and enhanced mildness by ethylene oxide-propylene oxide copolymers. As described in these various patents, the addition of polymers to LDLDs can aid performance in many important attributes of the product. 

Schwuger [4] has investigated the effects of ether groups on the solubility, surface properties, and detergency of alkyl ether sulfates. Addition of ethylene oxide groups to the alkyl surfactants increases solubility, thus reducing the formation of precipitates and maintaining foam volume in the presence of Ca2+ and Mg2+ ions. The use of ether sulfates would be preferred over that of alkyl sulfates for a clear formulation. 

There have been a limited number of studies on the effects of enzymic modification of protein concentrates on functional properties other than solubility. Studies on functional properties, as modified by enzymic treatments, emphasize foam formation and emulsifying characteristics of the hydrolysates. Treatment of chicken egg albumen alters the functional properties of the egg proteins in terms of foam volume and stability and the behavior of the proteins in angel food cakes (25). Various proteolytic enzymes were used to degrade the egg albumen partially. However, proteolytic enzyme inhibitors indigenous to the egg proteins repressed hydrolysis of the egg proteins compared with casein. 

Effects of ethoxylation of alkyl ether sulfates on solubility, surface properties, and detergency have been discussed in the literature. Ethoxylation of alkyl surfactants not only increases solubility, but also helps reduce the tendency for precipitation and decrease in foam volume in the presence of calcium and magnesium ions from hard water. 

Flammability Acrolein is very flammable its flash point is <0° C, but a toxic vapor cloud will develop before a flammable one. The flammable limits in air are 2.8% and 31.0% lower and upper explosive limits, respectively by volume. Acrolein is only partly soluble in water and will cause a floating fire, so alcohol type foam should be used in firefighting. The vapors are heavier than air and can travel along the ground and flash back from an ignition source. 

Denaturation is a change in which the natural protein becomes insoluble in solutions in which it was previously soluble. It is brought about by physical means such as heat, pressure, and surface force, or by chemical means, although very few chemical agents are used in this connection in the food field. Gel-type solutions are usually beaten before they become too thick or firmly set. As air is incorporated, the volume increases and the firmness of the gel stabilizer sets the foam. 

A mixture of ammonium chloride and borax was one of the treatments of cellulosic fabrics reported by Gay-Lussac in 1821. Due to its low dehydration temperature and water solubility, sodium borates are only used as flame retardants in cellulose insulation (ground-up newspaper— see Sections 9.2.1.2 and 9.2.2.1), wood timber, textiles, urethane foam, and coatings. For example, a mixture of urethane (100 parts), borax (100 phr), and perlite (30phr) was claimed to provide flame-retardant urethane foam.8 Borax in conjunction with boric oxide, silica, ammonium chloride, and APB as ceramizing additives and volume builders, are claimed in a fire-protection coating based on polybutadiene and silicone microemulsion.9 Using a modified DIN 4102 test, the chipboard with the coating showed a loss of mass less than 1% and there was no pyrolysis of the wood sample. 

It is known that some slightly soluble in water hydrocarbons brought in contact with a foam, decrease its stability. This phenomenon is observed in petrol industry or in firefighting of gasoline, kerosene and other petroleum products [41-45], The presence of a hydrocarbon in the foaming solution affects considerably the volume and stability of the foam [44,45]. The study of foaming of complex compositions, for example, a system containing aqueous solution of sodium salts of abietic and myristic acid, has shown that there occurs self-... 

At the bottom of the vessel there is a perforated barrier with a hermetically sealed filter paper on it. The foam column height is 50 mm. After foam formation a reduced pressure is created in the space below the barrier which is by 3 kPa less than the atmospheric (the absolute pressure is 97 kPa). The foam is dried for 10 min. Then the upper foam layer is brought into contact with another filter over which a solution of the NaDoBS and water-soluble fraction of thymol blue and NaCI are placed. The pressure in the space above this filter is 99.3 kPa to ensure a 1.3 kPa total pressure drop in the foam. Under the pressure drop the mixture enters the foam and through the Plateau borders advances from top to bottom. The liquid outflow is collected in a microtrap and samples of ca. 0.2 ml volume are taken to analyse the concentrations of the sulphonate and the dye. 

A direct relation between the polymer foams density (respectively, the expansion ratio) and the oligomer content in it has been established [114], Addition of water soluble polymers (polyvinyl alcohol, carboxymethyl cellulose, etc.) led to a reduction in resin consumption without deteriorating the quality of the solid foam obtained. Polymer foams of density 5-7 kg m3 were produced when the oligomer consumption was not more than 15-20% with respect to the solution volume. 

When two dissimilar plastic foams are to be joined, which is rarely done, adhesive bonding is generally preferable because of solvent and polymer incompatibility problems. Solvents used to cement plastics should be chosen with approximately the same solubility parameter (5) as the plastic to be bonded. The solubility parameter is the square root of the cohesive energy density (CED) of the liquid solvent or polymer. CEDs of organic chemicals are primarily derived from the heat of vaporization and molecular volume of the molecules, and are expressed as calories per cubic centimeter (cal/cm ). Literature sources provide data on 6 s of a number of plastics and resins (2) (3) (4). 

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