Water Based Systems

Naturally occurring polysaccharides and their derivatives form the predominant group of water-soluble species generally used as thickeners to impart viscosity to treating fluids [1092]. Other synthetic polymers and biopolymers have found ancillary applications. Polymers increase the viscosity of the fi ac-turing fluid in comparatively small amounts. The increase in fluid viscosity of hydraulic fracturing fluids serves for improved proppant placement and fluid loss control. Table 17 summarizes polymers suitable for fracturing fluids. 

Polymer from N-vinyl lactam monomers, vinyl sulfonates [175] 

Anionic galactomannans, which are derived from guar gum, in which the hydroxyl groups are partially esterified with sulfonate groups that result from 2-acrylamido-2-methylpropane sulfonic acid and l-allyloxy-2-hydroxypropyl sulfonic acid [1872], have been claimed to be suitable as thickeners. The composition is capable of producing enhanced viscosities, when used either alone or in combination with a cationic polymer and distributed in a solvent. 

Boron-crosslinked galactomannan fracturing fluids have an increased temperature stability. The temperature stability of fracturing fluids containing galactomannan polymers is increased by adding a sparingly soluble borate with 

Hydroxyethylcellulose can be chemically modified by the reaction with vinyl phosphonic acid in the presence of the reaction product of hydrogen 

Brominated flame retardant using antimony oxide as synergist. Effective on all natural, synthetic and blended textiles, non-wovens, paper, latexes and coatings. 

For 100% cotton work clothing used in the non ferrous metals industry. 

Non-dusting aqueous dispersion of Antimony Trioxlde compatible with PVC and PVDC latexes or chlorinated paraffin emulsions or dispersions. 

For disperse dyeable fibers such as polyester or polypropylene. Applied by padding or exhausting in a dyebath. 

Approved by California Fire Marshall and U.S. and NATO Armed Forces. 

---

Recovery and Purification. AH processes for the recovery and refining of maleic anhydride must deal with the efficient separation of maleic anhydride from the large amount of water produced in the reaction process. Recovery systems can be separated into two general categories aqueous- and nonaqueous-based absorption systems. Solvent-based systems have a higher recovery of maleic anhydride and are more energy efficient than water-based systems. 

Water-Based Muds. About 85% of all drilling fluids are water-based systems. The types depend on the composition of the water phase (pH, ionic content, etc), viscosity builders (clays or polymers), and rheological control agents (deflocculants or dispersants (qv)). 

Until the 1980s, synthetic organic solvents commonly were used in the United States to extract the caffeine, either by direct contact as above or by an indirect secondary water-based system (36). In each case, steaming or stripping was used to remove residual solvent from the beans and the beans were dried to their original moisture content (10—12%) prior to roasting. 

Hydrophilic/hydrophobic properties. In water-based systems, the filler should be compatible with water because filler dispersion occurs in an aqueous medium before a polymer emulsion is added. In general, most fillers are hydropho-... 

Synthetic-based muds are mineral oil muds in which the oil phase has been replaced with a synthetic fluid, such as ether, ester, PAO, or linear alkylbenzene, and are available from major mud companies. The mud selection process is based on the mud s technical performance, environmental impact, and financial impact. Synthetic muds are expensive. Two factors influence the direct cost unit or per-barrel cost and mud losses. Synthetic muds are the technical equivalent of oil-based muds when drilling intermediate hole sections. They are technically superior to all water-based systems when drilling reactive shales in directional wells. However, with efficient solids-control equipment, optimized drilling, and good housekeeping practices, the cost of the synthetic mud can be brought to a level comparable with oil-based mud [1308]. 

In particular. Table 17-2 reflects the complexity of a fracturing fluid formulation. Some additives may not be used together reasonably, such as oil-gelling additives in a water-based system. More than 90% of the fluids are water based. Aqueous fluids are economical and can provide control of a broad range of physical properties as a result of additives developed over the years. 

Installation of a water-based electrostatic immersion painting system to replace a solvent-based painting system. The water-based system resulted in a waste solvent reduction of more than 95%. 

Water spray systems for hydrocarbon facilities are routinely specified because of the rapid application means the system can provide and the excellent heat absorption a water based system represents. Water sprays are also used when passive fire protection measures (i.e., fireproofing, spacing, etc.) cannot practically be utilized. The key to providing an effective system is to ensure the surfaces to be protected receive adequate water densities and that the arrangements to activate the system are equally fast acting. By far the highest... 

Journal of Coatings Technology 72, No. 905, June 2000, p.67-72 FORMULATING WATER-BASED SYSTEMS WITH PROPYLENE-OXIDE-BASED GLYCOL ETHERS... 

To comply with environmental legislation, coatings formulators have reformulated to water-based systems, which has wide-ranging effects on the properties of their products. Reformulating with non-hazardous air pollutants solvents such as propylene-oxide-based glycol ethers helps reduce VOC content, and is the subject of this detailed paper. 6 refs. 

This isoindoline nickel complex pigment is mainly recommended for the coloration of metallics and effect coatings, especially for water based systems. P.R.271 affords yellowish to medium red shades, providing a bright flop in metallics. Alkyd/melamine resin systems may safely be overcoated and withstand exposure of 140°C for 30 minutes. The flow properties of P.R.271 in these systems and in polyester cellulose acetobutyrate base coat systems are good, but there is a certain tendency to flocculate. 

Incorporated in plasticized PVC, P.B.15, like other phthalocyanine pigments, is usually entirely fast to migration. Moreover, it provides excellent lightfastness. P.B.15 also finds use in various types of PUR foam materials as well as in rubber. Its redder and frequently cleaner shade compared to corresponding stabilized types makes it an equally useful pigment for other media. This applies especially for water-based systems. Textile printing, paper mass coloration, paper surface treatment, and paper pulp are areas of application as suitable for the use of P.B.15 as office articles, including colored pencils, blackboard chalks for schools, and water colors. 

Intumescent materials, which are water-based systems, cure by evaporation. If applied during periods of high humidity, the areas of application may experience blistering when the humidity drops and the evaporative curing continues. In such environments, solvent-based materials are recommended. 

The substitution of chemical solvents by water in paint and coating systems and also in cleaning processes creates complex evaluation issues, as the number of the various chemical components contained in the corresponding products generally increases. In addition, the release of persistent substances into the aquatic environment tends to be favoured by this. This therefore raises the question for assessing two suitable strategies containment of known hazardous substances in closed systems or substitution of the mobile solvent by complex water-based systems that are scarcely evaluable from a toxicological aspect. 

Dispersants function through various mechanisms. For water-based systems the preferred mechanism is stabilisation by ionic repulsion. A repulsion force layer is formed around the mineral particle. To maintain the suspension stability, the thickness of this layer around each particle has to be increased with increasing particle size. Layer decay is more frequent with the use of small particles, which results in higher proneness to partial flocculation. Also a uniform layer is necessary for effective stabilisation of all dispersed particles. AMP-95 helps to achieve all these requirements. 

Water-based UV systems are gaining the most acceptance where the finishing must look like a traditional lacquer or varnish. Most water-based UV finishes confain 30-35% solids. Currently, it appears that the optimum UV system is a combination of a 100% solids system and water-based system on many wood products. One hundred percent solids finishes are used for sealing and filling the wood. When the wood is filled or sealed as desired, it can be cured and immediately sanded. Then the water-based UV system is applied to get the traditional look without the VOCs and in fewer steps than a traditional wood finish. ... 

Chelating agents (chelants for short) form complexes with metal ions in solution either to prevent metal ions from causing undesirable reactions or to transport metal ions to where they are needed. Chelants are normally used in water-based systems where metal ions are nearly always present and require control. To understand how and why chelants are used, it is worth spending a short time considering water as a solvent and the effect that metal ions have on the use of water as a solvent in industry and the home. 

Some surfactants undergo an aggregation process in hydrocarbon and other nonpolar solvents. Th forces involved in surfactant aggregation with nonaqueous solvents must differ considerably from those already discussed for water-based systems. The orientation of the surfactant relative to the bull solvent will be opposite to that in water therefore, these systems are referred to as reverse micelles, These micelles will not have any signiLcant electrical properties relative to the bulk solvent (Luisi etal., 1988). 

Figure 12 Scheme of a modular MEMFRAC distillation unit for fractionation of non-water-based systems, developed at the TNO Institute. (From Ref. 227.)... 

Generally, there are two basic types of inks. The first type contains finely dispersed carbon black or colored pigments in both solvent and water based systems. Pronounced improvements have been achieved in stabilizing aqueous pigment formulations for ink-jet applications by adding specific polymeric dispersing agents [18], The second type of ink is based on water or solvent soluble dyes. 

---