Surfactant in emulsion

Anionic surfactants are the most commonly used surfactants in emulsion polymerization [Blackley, 1975 Gardon, 1977]. These include fatty acid soaps (sodium or potassium... 

Chen, J., Dickinson, E. (1995). Protein-surfactant interfacial interactions. Part 3. Competitive adsorption of protein + surfactant in emulsions. Colloids and Surfaces A Physicochemical and Engineering Aspects, 101,77-85. 

Large volumes of soap are used in industrial applications as gelling agents lor kerosene, paint driers, and as surfactants in emulsion polymerization. See also Soaps. Concern over water eutrophication resulted in a ban of phosphorus in laundry detergents. Phosphates have been effectively replaced by combinations of zeolite, citrate, and polymers, coupled with rebalanced synthetic active systems. Soap itself is generally present only as a minor component of surfactants. 

Ferguson et al. [52] compared the behavior of a range of conventional alkyl ethoxylate surfactants in emulsion polymerizations with their acrylated analogues. This has allowed a direct comparison of identical surfactant structures, one of which remains kinetically mobile in the resultant lattices, while the other becomes chemically bound to the latex particles. The surfactants chosen for this study were C12 i4-(EO)30 with C12 14-(EO)30-A and C12 14-(EO)12 with C12 14-... 

Guyot, A. and Tauer, KReactive Surfactants in Emulsion Polymerization. Vol. Ill, pp. 43-66. 

Inisurfs, Transurfs and Surfmers may be used to reduce/avoid the use of conventional surfactants in emulsion polymerization. However, when Inisurfs and Transurfs are used, the stability of the system cannot be adjusted without affecting either the polymerization rate (Inisurfs) or the molecular weight distribution (Transurfs). Furthermore, the efficiency rate of Inisurfs is low due to the cage effect. It is therefore not obvious yet that these classes will become commercially significant. 

The concept of using reactive surfactants in emulsion polymerization processes is relatively recent and aims at eliminating the drawbacks associated with the use of conventional, monomeric, nonreactive surfactants. Despite the demonstrated advantages and the availability of commercial products, reactive surfactants have not yet reached a widespread... 

Guyot, A. and Vidal, F. (1995) Inifer surfactants in emulsion polymerisation. Polym. Bull, 34, 569-76. 

Abele, S., Graillat, C., Zigmanis, A. and Guyot, A. (1999) Hemiesters and hemiamides of maleic and succimic acid synthesis and application of surfactants in emulsion plymerization with styrene and butyl acrylate. Polym. Adv. Technol, 10, 301-10. 

Interfacial Film of Surfactants. The droplets are surrounded by an interfacial film of surfactant in emulsion systems. The stability of such films can be increased by adding appropriate surfactants. 

The droplet deformation increases with increases in the Weber number which means that, in order to produce small droplets, high stresses (i.e., high shear rates) are require. In other words, the production of nanoemulsions costs more energy than does the production of macroemulsions [4]. The role of surfactants in emulsion formation has been described in detail in Chapter 10, and the same principles apply to the formation of nanoemulsions. Thus, it is important to consider the effects of surfactants on the interfacial tension, interfacial elasticity, and interfacial tension gradients. 

Most reports on emulsion polymerisation have been limited to commercially available surfactants which, in many cases, are relatively simple molecules such as sodium dodecyl sulphate and simple nonionic surfactants. However, studies on the effects of surfactant structure on latex formation have revealed the importance of the structure of the molecule. Block and graft copolymers (polymeric surfactants) are expected to be better stabilisers when compared to simple surfactants. The use of these polymeric surfactants in emulsion polymerisation and the stabilisation of the resulting polymer particles is discussed below. 

Role of Surfactants in Emulsion Polymerization Technology Formation of aggregates as micro-reactors... 

Fig. 2 Schematic representation of emulsion pol5onerization. (a) Role of surfactants in emulsion polymerization technology, (b) Emulsion polymerization process...

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