Emulsifiers types

However, the kinetics of PVC emulsion does not foUow the above theory. The rate shows the same increasing behavior with conversion as mass polymerization (94,95). [N depends on [3], but the relationship varies with the emulsifier type (96,97). However, the rate is nearly independent of [N (95). The average number of radicals per particle is low, 0.0005 to 0.1 (95). The high solubiUty of vinyl chloride in water, 0.6 wt %, accounts for a strong deviation from tme emulsion behavior. Also, PVC s insolubiUty in its own monomer accounts for such behavior as a rate dependence on conversion. 

Ionic emulsifier type Stable latex Unstable latex... 

Sealing electrical bushings and terminals. Used instead of silicone oils in vacuum pumps. May have been added to automotive transmission oils to swell shrunken transmission seals in place. Ingredient in emulsifiable-type cuttings oils to increase heat resistance (Monsanto, 1960). 

Mun, S., Decker, E.A., McClements, D.J. (2007). Influence of emulsifier type on in vitro digestibility of lipid droplets by pancreatic lipase. Food Research International, 40, 770-781. 

In another set of studies, it has been reported that the in vitro digestibility of lipid droplets by pancreatic lipase is significantly affected by emulsifier type (Mun et al, 2006, 2007 Park et al., 2007). Intuitively, one might expect that a thick dense layer of strongly bound protein-polysaccharide complex at the oil-water interface would reduce considerably the in vivo accessibility of lipases, and hence would reduce the rate of human metabolism of fats. Establishment of the validity of this hypothesis must still await consolidation of a substantial body of detailed results from independent systematic studies on a broad range of mixed biopolymer systems. 

The experimental factors that affect the stability of the latex during and after polymerization are the recipe used for the polymerization, the type and intensity of agitation during and after the polymerization, the temperature of polymerization and storage, and the age and storage conditions of the latex. The recipe used in the polymerization included the mode of polymerization, the monomer-water ratio, the solubility of the monomer in water, the emulsifier type and concentration, initiator type and concentration, total electrolyte concentration, and impurities present in the system. 

Mayhill, P.G., Newstead, D.F. 1992. The effect of milkfat fractions and emulsified type on creaming in normal-solids UHT recombined milk. Milchwissenschaft. 47, 75-79. 

The effects of the concentration of the dispersed phase, emulsifier type and concentration on the inversion of water-in-oil emulsions have been described above. However, since in this chapter, it is proposed to examine the effects of a multi-ingredient system on emulsion stability, each of the following factors must be considered emulsion formation, stability, instability, effects of shear and effects of ingredients (Becher, 1977). 

Suitable Diluent Water Emulsifier Type Nonionic... 

Total Solids 38.0% pH 5% Solution 7.0 Active Silicone 35.0 Emulsifier Type Nonionic... 

The number of particles is a function of emulsifier type and concentration and initiator level, although for monomers that obey Case 1 kinetics such as vinyl chloride and vinyl acetate, is almost independent of initiator level (Ugelstad et al, 1969 Friis and Nyhagen, 1973). The calculation of iVp for various reactor operations will he discussed later. The monomer concentration in the polymer particle [Mp] can he obtained using a simple mass balance. Assuming the monomer and pdymer volumes are additive, one obtains the following relationship for the conversion interval,... 

The size of the droplets in an emulsion has a strong influence on many of its physicochemical and sensory properties, e.g., shelf life, appearance, texture, and flavor (1,2, 4). For example, the stability of an emulsion to gravitational separation or droplet aggregation can be greatly improved by decreasing the droplet size. This is because the velocity of sedimentation is proportional to the square of the droplet size. The size of the droplets in an emulsion is largely determined by the emulsifier type and concentration, the physicochemical properties of the component phases, and the homogenization conditions (4). A food manufacturer normally specifies a preestablished desirable droplet size distribution for a particular product. If the product does not meet this specification, it typically must be reprocessed or even discarded. 

Emulsifier Type and Concentration For a fixed concentration of oil, water, and emulsifier, there is a maximum interfacial area that can be completely covered by an emulsifier. As homogenization proceeds, the size of the droplets decreases and the interfacial area increases. Once the emulsion interfacial area increases above a certain level, there may be insufficient emulsifier present to completely cover the surface of any newly formed droplets. This will not only increase the energy required for subsequent droplet dismption but also increase the probability for droplet coalescence. The minimum size of stable droplets that can be produced during homogenization is governed by the type and concentration of emulsifier present ... 

The PhEur 2005 also contains specifications for cetostearyl alcohol, emulsifying Type A, and Type B, respectively. 

The formation and stabilization of 0/W emulsions prepared with mixed emulsifier systems has been extensively investigated. However, the mechanisms proposed differ greatly. One of the primary hypotheses attributes the enhanced stability to the formation of a molecular "complex" or layer at the oil/water interface (8-11). The mixture of emulsifier types increases the packing density of the adsorbed interfacial film. Several investigators have shown that more closely packed complexes produce more stable emulsions (9,12-14). Friberg, et al. (15-17) have attributed the enhanced stability of mixed emulsifier emulsions to the formation of liquid crystals at the oil/water interface, which reduce the van der Waals attractive forces. 

Table 3.36 Common food emulsifier types and origin...

Osborn, H. T. and Akoh, C. C. (2004). Effect of emulsifier type, droplet size, and oil concentration on lipid oxidation in structured lipid-based oil-in-water emulsions. Food Chem. 84, 451—456. 

There are a large variety of E-SBR types based on the styrene content, polymerization temperature, antioxidants, oil and carbon black content. Each of these basic classifications includes a variety of SBR polymer variations with respect to Mooney viscosities, coagulation types, emulsifier type, oil levels, and carbon black types and levels. Table 2 shows the basic series of E-SBR. 

Fats and vegetable oils, including tall oil are renewable resources for surfactants. The soaps of natural fatty acids and dispropoitimiated rosin soaps are the most important emulsifier types for the production of synthetic mbber, and sodium or ammonium salts of fatty acids and hydroxy fatty acids are also largely used in PVC manufacturing. 

Ostberg et al. [210] have investigated in detail the influence of the emulsifier type and alkyd properties on droplet size and stability of alkyd emulsions. Alkyd S-68 (Bergvik Kemi AB, Sweden) was mainly used as an alkyd resin, containing 67.8% of oil, acid value=10.6, viscosity=680 mPa s. Other oils were also used, with acid values 8-9 and viscosities from 180 to 970 mPa s. The surfactants used were ... 

Donsi, R Sessa, M. Rerrari, G., Effect of emulsifier type and disruption chamber geometry on the fabrication of food nanoemulsions by high pressure homogenization. Industrial and Engineering Chemistry Research (2012) 51, 7606-7618. 

The factors that affect the adhesiveness of the emulsion and thus of the bitumen with the aggregates are as follows the emulsifier type and quantity, the bitumen quality and grade, the pH of the aqueous solution of the emulsifier and the type of aggregates. 

Table 1. The effects of emulsifier type on the stability of pre-emulsion and resulting latex for VAc/EXDM system...

Cetostearyl alcohol (type B) concerning the emulsifier (type A sodium cetostearyl sulfate type B sodium lauryl sulfate). The macrogols are followed by a number, which indicates the average molecular mass of the chain. 

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