Lower-viscosity

Strong acids completely hydrolyse cellulose to glucose very mild hydrolysis gives hydrocelluloses with shorter chains and lower viscosity and tensile strength. Under special conditions a large yield of cellobiose is obtained. 

Viscosity is measured in poise. If a force of one dyne, acting on one cm, maintains a velocity of 1 cm/s over a distance of 1 cm, then the fluid viscosity is one poise. For practical purposes, the centipoise (cP) is commonly used. The typical range of gas viscosity in the reservoir is 0.01 - 0.05 cP. By comparison, a typical water viscosity is 0.5 -I.OcP. Lower viscosities imply higher velocity for a given pressure drop, meaning that gas in the reservoir moves fast relative to oils and water, and is said to have a high mobility. This is further discussed in Section 7. 

Liquid ammonia, which boils at 240 K, is an ionising solvent. Salts are less ionised in liquid ammonia than they are in water but, owing to the lower viscosity, the movement of ions through liquid ammonia is much more rapid for a given potential gradient. The ionisation of liquid ammonia... 

We must be careful in assessing the experimental results on the viscosity of branched polymers. If we compare two polymers of identical molecular weight, one branched and the other unbranched, it is possible that the branched one would show lower viscosity. Two considerations enter the picture here. First, since the side chains contribute to the molecular weight, the backbone chain... 

Thickeners. These are used to kicrease viscosity of shampoos to achieve certain consistency characteristics ki the product, from a thickened Hquid to gels and pastes. Among the most important materials used for this purpose are the alkanolamides. The chain length of the amide alkyl group and its solubiHty ki the shampoo system are important aspects to be considered ki thek use for effects on viscosity. In general, as the chain length increases the viscosity response improves. The viscosity increase also is related to the water solubiHty of the amide the more water-soluble forms provide a lower viscosity response than the less soluble amides. 

A second type of uv curing chemistry is used, employing cationic curing as opposed to free-radical polymerization. This technology uses vinyl ethers and epoxy resins for the oligomers, reactive resins, and monomers. The initiators form Lewis acids upon absorption of the uv energy and the acid causes cationic polymerization. Although this chemistry has improved adhesion and flexibility and offers lower viscosity compared to the typical acrylate system, the cationic chemistry is very sensitive to humidity conditions and amine contamination. Both chemistries are used commercially. 

The component with the lower viscosity tends to encapsulate the more viscous (or more elastic) component (207) during mixing, because this reduces the rate of energy dissipation. Thus the viscosities may be used to offset the effect of the proportions of the components to control which phase is continuous (2,209). Frequently, there is an intermediate situation where a cocontinuous or interpenetrating network of phases can be generated by careflil control of composition, microrheology, and processing conditions. Rubbery thermoplastic blends have been produced by this route (212). 

Mliphatic dibasic acids such as succinic acid, adipic acid, azelaic acid, and sebacic acids have also been used to make alkyd resins. Their linear chain stmcture lends higher flexibiUty and lower viscosity to the resin as compared to the rigid aromatic rings of phthaUc acids. 

This is because the effect of the dispersed soHd, rather than the dispersing medium, is usually more significant. However, the latter should not be ignored. Many industrial problems involving unacceptably high viscosities in dispersed systems are solved by substituting solvents of lower viscosity. 

Other Factors Affecting the Viscosity of Dispersions. Factors other than concentration affect the viscosity of dispersions. A dispersion of nonspherical particles tends to be more viscous than predicted if the Brownian motion is great enough to maintain a random orientation of the particles. However, at low temperatures or high solvent viscosities, the Brownian motion is small and the particle alignment in flow (streamlining) results in unexpectedly lower viscosities. This is a form of shear thinning. 

Density Difference Between Particle and Liquid. Separation cannot take place if A6 = 0. Some mineral oils have the same density as water at room temperature. If it is heated to 80°C, the reduction of the density of water is less than that of the mineral oil, resulting ia the water becoming heavier. Therefore separation is possible. Dilution of a Hquid by a solvent, eg, molasses by water or heavy oil by naphtha, results ia lower density and lower viscosity of the Hquid. Solvent stripping takes place at a later stage. 

Sulfur as an Additive for Asphalt. Sulfur-extended asphalt (SEA) binders are formulated by replacing some of the asphalt cement (AC) in conventional binders with sulfur. Binders that have sulfur asphalt weight ratios as high as 50 50 have been used, but most binders contain about 30 wt % sulfur. Greater latitude in design is possible for SEA paving materials, which are three-component systems, whereas conventional asphalt paving materials are two-component systems. Introduction of sulfur can provide some substantial benefits. At temperatures above 130°C, SEA binders have lower viscosities than conventional asphalt. The lower viscosity enables the plant to produce and compact the mix at lower temperatures than with conventional... 

Liquid Asphalt. Liquid asphalt products comprise cutback asphalts and emulsions. A number of grades of different viscosities are available, which permit appHcation from ambient temperatures to 150°C. The lower viscosity products are used for dust-laying purposes and as tack coats, prior to laying asphalt surface courses. The heavier grades are used for mix-in-place road mixes. 

The increase in fuel viscosity with temperature decrease is shown for several fuels in Figure 9. The departure from linearity as temperatures approach the pour point illustrates the non-Newtonian behavior created by wax matrices. The freezing point appears before the curves depart from linearity. It is apparent that the low temperature properties of fuel are closely related to its distillation range as well as to hydrocarbon composition. Wide-cut fuels have lower viscosities and freezing points than kerosenes, whereas heavier fuels used in ground turbines exhibit much higher viscosities and freezing points. 

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