Polymeric thickeners

In secondary operations, where chemicals are injected into hydrocarbon formations in conjunction with a chemical flooding process, polyamines are used to reduce the loss of injected chemicals to the formation by adsorption and precipitation (312). TEPA and other ethyleneamines are used with water-soluble polymeric thickeners in water—flood petroleum recovery operations to stabilize viscosity, mobiUty, and pH while imparting resistance to hydrolysis (313). 

Several systems may be used such as polymeric thickeners, fine particulate solids such as bentonite clays and oxides or combinations of the latter with polymers (1). The nature and level of the gelling agent required to prevent appreciable settling of particles and formation of hard "cakes" or clays depends on the density difference between disperse phase and medium, volume fraction of the disperse phase and interaction of the antisettling system with particles of the pesticide. 

Surfactant complex with associative polymeric thickener... 

Toussaint, Oldenhove, Broze Colgate Light-duty liquid composition containing gelatin beads and polyacrylate thickener Stably suspended oil containing gelatin beads with a polyacrylate polymeric thickener... 

Currently, products in the market are thickened mainly by polyacrylic acids, although some use a mixture of polymer and a clay. This is in contrast to the early LADD products, which used exclusively clay thickeners and therefore suffered from stability problems [7], The products, being clay suspensions in an aqueous medium, tended to separate in a relatively short period of time. The introduction of bleach-compatible polymeric thickeners in the early 1990s overcame this problem [75],... 

U.S. 5169552 (1992) [64] Wise (Procter Gamble) Polymeric thickener stabilizing agent buffering agent Improved bleach stability improved rheology shear thinning... 

Suspend without crystalline suspending agents or hydrophilic polymeric thickeners have good, nonslimy feel... 

Polymeric thickeners Gums Acacia Alginates Carageenan Chitosan Collagen Tragacanth Xantham Celluloses Sodium carboxymethyl Hydroxyethyl Hydroxypropyl Hyd roxypro pyl m ethyl Acrylic acids Carbomers Polycarbophil Colloidal solids Silica Clays Microcrystalline cellulose Hydrogels Polyvinyl alcohol Polyvinylpyrrolidone Thermoreversible polymers Poloxamers... 

Polymeric thickening agents used in foods typically are well soluble polysaccharides, with an excluded volume parameter [j clearly above zero. This implies that especially the dilute and semidilute regimes are often of importance. Viscosity of very dilute solutions has been discussed in Sections 6.2.2 and 6.3.2. For higher concentrations, the reduced viscosity (j sp/c) is higher, as is true for any system (see Figure 5.5), but for polymer solutions the viscosity increases far stronger with concentration as soon as the chain overlap concentration is reached. 

Mackay and coworkers [33,34] and Moss and coworkers [35] showed that reactions of nucleophiles with phosphorus(V) esters, which are models for nerve agents, can be carried out effectively in microemulsions. The active agents often contain polymeric thickeners, and the solubilizing power of microemulsions is of crucial importance. Typically cationic surfactants are used with alcohols or alMpyrollidinones as cosurfactants. lodosobenzoate ions (2) are nucleophilic turnover catalysts toward fluorophosphonate nerve agents and phosphate esters, and Moss and coworkers used amphiphilic iodosobenzoate ions extensively in this work [36] (see Scheme 2). 

V Gallardo, AV Delgado. A Parera. J Salcedo. Electrophoretic study of nitrofurantoin in aqueous suspensions. Effect of the addition of a polymeric thickener. J. Pharm. Phannacol, 42 225-229, 1990,... 

Uses Emulsifier for paints, emulsion polymerization thickener, emulsifier for printing pastes emulsifier, thickener for cosmetics gloss aid, pearlescent for shampoos... 

Uses Monomer for emulsion polymerization thickener, dispersant, suspending agent copolymerizable stabilizer bound protective colloid modifying comonomer/crosslinker Trade Name Synonyms Sipomer HEM-5 [Rhodia HPCII http //www.rhodia-hpcii.com] PEG-6 methacrylate CAS 25736-86-1 (generic)... 

Characterization of polymeric thickeners used in the formulation of sealants and adhesives. Polymers of this type are frequently used to provide protective coatings - in rust-preventative products for example. 

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