Copolymers nonionic surfactants

Table 2.3 Structure and Commercial Denomination of the Block Copolymer Nonionic Surfactants of the Pluronic Series ...

Figure 5.2.4 shows a network surface structure of a VA/AA-based emulsion with 6.6 wt% soiids. The repeat unit in the network structure is between 5 and 10 jtm. The formation of the network or bicontinuous surfactant structure is well established in relatively high molecular weight ethylene oxide/propylene oxide segmented block copolymer nonionic surfactants, and it has been ascribed to the formation of liquid crystalline macromolecular assemblies. Upon dilution, the emulsion showed 5-10 ttm spherical domains that could form aggregates up to about 60p.m in size (Fig. 4.4.5). In Fig. 5.2.5, bubble surfaces are shown with the network surfactant structure, even in the diluted emulsion. Apparently, the surfactant macromolecules tend to concentrate on bubble surfaces and form a more viscous and probably elastic polymer surface layer. 

EO and PO block copolymers, nonionic surfactants with molecular weight of 8000 amu, that is, Pluronics and Proxanols, are good emulsifiers for fluorocarbons. However, their effectiveness varies for different types of fluorinated organic liquids [55-58]. 

An FEP copolymer dispersion is available as a 55-wt % aqueous dispersion containing 6% nonionic surfactant (on a soflds basis) and a small amount of anionic dispersiag agent. Its average particle size is ca 0.2 p.m. 

Nonionic Surfactants Polyoxyalkylene Block Copolymers, edited by Vaughn M. Nace... 

The poloxamers manufactured by BASF (Cheadle, UK) are known as Pluronic PE block copolymers those manufactured by ICl (Cleveland, UK) as Synperonic PE nonionic surfactants. 

Nonionic surfactants, including EO-PO block copolymers, may be readily separated from anionic surfactants by a simple batch ion exchange method [21] analytical separation of EO-PO copolymers from other nonionic surfactants is possible by thin-layer chromatography (TLC) [22,23] and paper chromatography [24], and EO-PO copolymers may themselves be separated into narrow molecular weight fractions on a preparative scale by gel permeation chromatography (GPC) [25]. 

Ethylene oxide is an important intermediate chemical not only for the production of nonionic surfactants like fatty alcohol ethoxylates, alkylphenol ethoxy lates, or propylene oxide/ethylene oxide block copolymers, but also for manufacturing of anionic surfactants like alcohol ether sulfates. 

Gilsonite is active as a fluid loss additive because the permeability of cement is reduced. Latex additives also act as fluid loss additives. They also act as bonding aids, gas migration preventers, and matrix intensifiers. They improve the elasticity of the cement and the resistance to corrosive fluids [921]. A styrene-butadiene latex in combination with nonionic and anionic surfactants shows less fluid loss. The styrene-butadiene latex is added in an amount up to 30% by weight of the dry cement. The ratio of styrene to butadiene in the latex is typically 2 1. In addition, a nonionic surfactant (octylphenol ethoxylate and polyethylene oxide) or an anionic surfactant, a copolymer of maleic anhydride, and 2-hydroxypropyl acrylate [719] can be added in amounts up to 2%. 

V M Nace, Nonionic surfactants polyoxyalkylene block copolymers (New York Marcel Dekker, 1996). 

Chu B, Zhou Z (1996) Physical chemistry of polyoxyalkylene block copolymer surfactants. In Nace VN (ed) Nonionic surfactants polyoxyalkylene block copolymers, vol 60. Marcel Dekker, New York... 

V.M. Nace, Nonionic Surfactants Polyoxyalkylene Block Copolymers, Surfactant Science Series, Vol. 63, Marcel Dekker, New York, USA, 1996. 

Edens, M. W. (1996). Applications of polyoxyethylene block copolymer surfactants. In Nonionic surfactants. Polyoxyalkylene block copolymers, Vol. 60, (ed. V. N. Nace), p. 185. Marcel Dekker, New York. 

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