Temperature water solubility

Urea-formaldehyde resins are used as the main adhesive in the forest product industry because they have a number of advantages, including low cost, ease of use under a wide variety of curing conditions, low cure temperatures, water solubility, resistance to microorganisms and to abrasion, hardness, excellent thermal properties, and a lack of color, especially in the cured resin. 

Ointment An unctuous semisolid for topical application. Typical ointments are based on petrolatum. An ointment does not contain sufficient water to separate into a second phase at room temperature. Water soluble ointments may be formulated with polyethylene glycol. 

In principle, there are two factors that will influence the catalytic activity First, the collapsed PNIPA layer probably presents a higher steric barrier for benzyl alcohol molecules to diffuse from bulk aqueous dispersion to the surface of AuNPs, causing the reaction to slow down (as shown in Fig. 8). Second, with the increase of temperature, water-soluble hydrophilic PNIPA networks become oil-soluble and hydrophobic, which is favorable for the diffusion of hydrophobic benzyl alcohol onto the AuNP surface (as shown in Fig. 14). Thus, the catalytic activity of Au composite particles should increase with increasing temperature. Figure 15 demonstrates that the second effect prevails over most of the temperature range the TOF value at 40°C... 

Water solubility (or aqueous solubility) is the maximum amount of a given substance that can dissolve in pure water at a particular temperature. Water solubility is a critical parameter, as drugs hitting the stomach must dissolve (be soluble) in gastric fluids to enable their absorption, transport, and delivery to target organs (e.g. the liver). The solubility of a substance in water is also helpful in determining the dispersion and fate of chemicals in the environment, and for this, water solubility is related to other chemical parameters (e.g. the octanol-water partition coefficient KOW). 

Published observations indicate that at room temperature water-soluble cellu-losics form mesophases at a critical volume fraction of polymer generally ranging from 0.3 to 0.5 for high molecular mass samples. For a given polymer and solvent, the critical volume fraction decreases with increasing molar mass, but increases with temperature. Highly polar and acidic solvents favor liquid crystal formation. 

Surface-active materials surface-active compounds may act as solubilizers and greatly affect the amount of test compound in the water phase. Temperature water solubility may increase or decrease with changes in the temperature, depending on the nature of the chemicals and the temperature range involved. 

Tool overhang should be kept to a minimum. Tools must be kept sharp to avoid buildup that can cause failure of the tool or the workpiece. A tool geometry similar to that used for cast iron is generally suitable. Liberal rake and clearance angles can be used. Cutting fluids are required to control the tool-tip temperature. Water-soluble cutting oils work well. 

High degree of water solubility at elevated temperatures. Water solubility in the presence of electrolytes. Excellent solvency at elevated temperatures. 

The quality of the final encapsulated lipid powder depends on a number of factors including, the amount of Hpid encapsulated, the fraction of lipid exposed to the environment, the long-term chemical stability of the lipid, the flowability of the powder, the dispersibility of the powder, etc. These parameters can be controlled by selecting appropriate concentrations and types of components to make up the initial emulsion, as well as appropriate operating parameters for the spray dryer (e.g. flow rates, inlet, and outlet temperatures). Water soluble polymers (such as proteins and polysaccharides) are often used as emulsifiers to stabilize oil-in-water emulsions prior to spray drying, and after re-dispersion of the dried powder into liquid. Alternatively, water soluble polymers may make up part of the wall material that helps encapsulate and protect the lipid in the powder during storage. 

Ben2onitri1e [100-47-0] C H CN, is a colorless Hquid with a characteristic almondlike odor. Its physical properties are Hsted in Table 10. It is miscible with acetone, ben2ene, chloroform, ethyl acetate, ethylene chloride, and other common organic solvents but is immiscible with water at ambient temperatures and soluble to ca 1 wt% at 100°C. It distills at atmospheric pressure without decomposition, but slowly discolors in the presence of light. 

Water-soluble peroxide salts, such as ammonium or sodium persulfate, are the usual initiators. The initiating species is the sulfate radical anion generated from either the thermal or redox cleavage of the persulfate anion. The thermal dissociation of the persulfate anion, which is a first-order process at constant temperature (106), can be greatly accelerated by the addition of certain reducing agents or small amounts of polyvalent metal salts, or both (87). By using redox initiator systems, rapid polymerizations are possible at much lower temperatures (25—60°C) than are practical with a thermally initiated system (75—90°C). 

Polydextrose (Pfizer) is prepared by high temperature polymerization of glucose in the presence of a catalyst. It is a water-soluble, amorphous soUd used primarily as a hulking agent (52). Dried fmit, including pmnes, and dried plum, date, and grape juice is used for similar appUcations (53). 

On the other hand, water-soluble PVA fibers are available on the market. They are stable in cool water but shrink in warm water and dissolve at 40 to 90°C. The dissolution temperature is controlled by the degree of polymerization and hydrolysis of PVA, he at-treatment conditions after spinning, etc. 

Margarine and butter contain fat plus water and water-soluble ingredients, eg, salt and milk soHds that impart flavor and color to the product. Generally these products are distributed at refrigerated temperatures to retain their quaHty. Greaseproof packaging, such as polyethylene-coated paperboard, aluminum foil/paper, parchment paper wraps, and polypropylene tubs, is used for butter and margarine (see Dairy substitutes). 

RVP is a vapor pressure measurement at a fixed air/Hquid ratio of 4 and a temperature of 38°C. It is measured under conditions of water saturation. For samples which contain water-soluble components such as alcohols, ASTM D4953 is used. 

Hitec Heat-Transfer Salt. Hitec heat-transfer salt, manufactured by Coastal Chemical Co., is an eutectic mixture of water-soluble inorganic salts potassium nitrate (53%), sodium nitrite (40%), and sodium nitrate (7%). It is suitable for Hquid-phase heat transfer at temperatures of 150—540°C. 

Volatilization. The susceptibility of a herbicide to loss through volatilization has received much attention, due in part to the realization that herbicides in the vapor phase may be transported large distances from the point of application. Volatilization losses can be as high as 80—90% of the total applied herbicide within several days of application. The processes that control the amount of herbicide volatilized are the evaporation of the herbicide from the solution or soHd phase into the air, and dispersal and dilution of the resulting vapor into the atmosphere (250). These processes are influenced by many factors including herbicide application rate, wind velocity, temperature, soil moisture content, and the compound s sorption to soil organic and mineral surfaces. Properties of the herbicide that influence volatility include vapor pressure, water solubility, and chemical stmcture (251). 

Water—Glycol Solutions. These materials are transparent solutions of water and glycol having good low temperature properties. They frequently contain water-soluble additives to improve performance in corrosion resistance, anti-wear, etc. A water-soluble polymer is commonly utilized to boost viscosity. As solutions their advantage over emulsions is their inherent stabdity. 

Borane—dimethyl sulfide complex (BMS) (2) is free of these inconveniences. The complex is a pure 1 1 adduct, ca 10 Af in BH, stable indefinitely at room temperature and soluble in ethers, dichioromethane, benzene, and other solvents (56,57). Its disadvantage is the unpleasant smell of dimethyl sulfide, which is volatile and water insoluble. Borane—1,4-thioxane complex (3), which is also a pure 1 1 adduct, ca 8 Af in BH, shows solubiUty characteristics similar to BMS (58). 1,4-Thioxane [15980-15-1] is slightly soluble in water and can be separated from the hydroboration products by extraction into water. 

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