Contents 2 Viscosity

Solution Polymers. Acryflc solution polymers are usually characterized by their composition, solids content, viscosity, molecular weight, glass-transition temperature, and solvent. The compositions of acryflc polymers are most readily determined by physicochemical methods such as spectroscopy, pyrolytic gas—liquid chromatography, and refractive index measurements (97,158). The solids content of acryflc polymers is determined by dilution followed by solvent evaporation to constant weight. Viscosities are most conveniently determined with a Brookfield viscometer, molecular weight by intrinsic viscosity (158), and glass-transition temperature by calorimetry. 

The physical properties of spray-dried materials are subject to considerable variation, depending on the direction of flow of the inlet gas and its temperature, the degree and uniformity of atomization, the solids content of the feed, the temperature of the feed, and the degree of aeration of the feed. The properties of the product usually of greatest interest are (1) particle size, (2) bulk density, and (3) dustiness. The particle size is a function of atomizer-operating conditions and also of the solids content, liquid viscosity, liquid density, and feed rate. In general, particle size increases with solids content, viscosity, density, and feed rate. 

Dissolved Solids Boiling Pt/Freezing Point For Liquids/Solid Mixtures Bulk Density Total Solids Content Solids Size Distribution Suspended Solids Content Suspended Solids Settling Rate Dissolved Solids Content Free Water Content Oil and Grease Content Viscosity For Gases Density... 

As a first step in the selection process, the applicability of the various solidification/ stabilization processes for specific contaminants can be determined using Table 12. Since these waste treatment systems vary widely in their applicability, cost, and pretreatment requirements, many are limited as to the types of waste that can be economically processed. Waste characteristics such as organic content, inorganic content, viscosity and... 

It was concluded that the rate varied with a number of factors, including N content, viscosity, the state of pulping of fibers, etc Ref D. Fensora, CaQadjR.es 26B, 59—69 (1948) CA 42, 4347(1948)... 

A wide variety of resists are available in these series covering different solids contents, viscosities, etc. 

Cotton Copper number Nitrogen content % Viscosity sec Solubility in alcohol %... 

Tempe- rature °C Nitrogen content % Viscosity sec Yield 0/ /o... 

Physical Property Variables. These variables are concerned with the physical properties of materials with the exception of those properties which are related to chemical composition and direct mass and weight. Variables included are density and specific gravity, humidity, moisture content, viscosity, consistency, and structural characteristics, such as hardness, ductility, and lattice structure. 

Product oils from SYNTHOIL runs carried out at 415° and 450° C and 2,000 and 4,000 psi H2 pressures were analyzed with respect to asphaltene and oil content, elementary compositions (C, E, S, N), ash and physical properties (specific gravity and viscosity). Asphaltenes exert a large effect on the viscosity of the product oil, the viscosity increasing exponentially with asphaltene content. Viscosity of product oil is not only dependent on the amount but also on the molecular weight of asphaltenes present. At 415° C, asphaltenes with a molecular weight of 670 are formed and at 450° C asphaltenes with a molecular weight of 460. 

Carr, T.P., Gallagher, D.D., Yang, C.-H., and Hassel, C.A. 1996. Increased intestinal contents viscosity reduces cholesterol absorption efficiency in hamsters fed hydroxypropyl methylcellulose. J. Nutr. 126, 1463-1469. 

Carr, T.P., Wood, K.J., Hassel, C.A., Bahl, R., and Gallaher, D.D. 2003. Raising intestinal contents viscosity leads to greater excretion of neutral steroids but not bile acids in hamsters and rats. Nutr. Res. 23, 91-102. 

Properties often used by epoxy resin manufacturers to specify particular grades of resin include the epoxy content, viscosity or softening point, and color. In addition, properties such as density, vapor pressure, flash point, refractive index, solubility characteristics, and hydroxyl content are often reported. The important properties of uncured epoxy formulations with regard to most adhesive applications are... 

Other Procedures. Residual monomer content, solids content, viscosities, F/T stability, and surface tension were determined as described... 

Molecular weights and molecular-weight distributions at high conversions are much less predictable and more dependent on the nature of the monomer. The two principal additional factors that come into play are chain transfer to polymer and the decrease of the rate coefficients for coupling and disproportionation with increasing polymer content, viscosity, and chain entanglement. 

The quality of the product is of primary importance in developing a recycling technology converting plastics into fuels by pyrolysis. Today the characterization of a liquid fuel from any sources is obviously based on the qualification methods and standards of fuels from mineral oil. The properties of the pyrolysis-derived fuels from plastics are expected to be similar to conventional fuels (energy content, viscosity, density, octane and cetane number, flash-point, etc.). However, in addition to the familiar ranking values it is necessary to know more about the chemical composition of the plastic pyrolysis oil, because of the peculiarities as follows ... 

Some fuel properties have long been known to be interrelated with chemical composition density and aromatic content, viscosity and distillation range, cetane number and aromatic content. Correlation studies applying various statistical computational methods revealed the contribution of chemical structural units of organic compounds to the various physical properties of hydrocarbon fluids, such as octane and cetane number, flash point, cloud point, etc. 

Among newly developed colon-specific drug delivery systems, pressure-controlled delivery capsules (PCDCs) [161] can be mentioned. Their mechanism of action is based on the relatively strong peristaltic waves taking place in the colon and leading to an increased luminal pressure. They consist of a capsular-shaped suppositories coated with a water-insoluble polymer (ethyl cellulose). Once taken orally, PCDCs behave like an ethyl cellulose balloon, because the suppository base liquefies at body temperature. In the upper GI tract, PCDCs are not directly subjected to the luminal pressures since sufficient fluid is present in the stomach and small intestine. The reabsorption of water in the colon provokes an increase of the luminal content viscosity. As a result, increased intestinal pressures directly affect the system via colonic peristalsis. Consequently, PCDCs mpture and drug release in the colon take place. 

The viscosity of an oil-in-water emulsion is sharply dependent on water content. Viscosity adjustment factors for water content may be obtained from a correlation such as that shown in Figure 3. In this figure, the adjustment factor is defined as 1.0 at the base level of 30% water. The actual correlation to be used is dependent on the base crude-oil content and other factors. 

Slow hydrolysis of cellulose acetate phthalate will occur under prolonged adverse conditions such as high temperatures and high humidity, with a resultant increase in free acid content, viscosity, and odor of acetic acid. However, cellulose acetate phthalate is stable if stored in a well-closed container in a cool, dry place. 

The presence of NaCl has an important effect on initial viscosities. As seen in Figure 6 for Shell crude emulsions containing 3.0 and 4.0 x 10 moles NaOH/gram oil, the addition of NaCl first lowers the viscosities which go through minima and then rise with further addition of NaCl. At the optimum NaCl contents, viscosities were about 13% lower than the salt-free emulsions. 

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