Viscosity types

In order to "cure" or "vulcanize" an elastomer, ie, cross-link the macromolecular chains (Fig. 2), certain chemical ingredients are mixed or compounded with the mbber, depending on its nature (4,5). The mixing process depends on the type of elastomer a high viscosity type, eg, natural mbber, requires powerhil mixers (such as the Banbury type or mbber mills), while the more Hquid polymers can be handled by ordinary rotary mixers, etc (see Rubber... 

Sodium alginate (algin) is one of the most widely used hydrocolloids for ice cream. It is supplied in several viscosity types. The lower viscosity material is recommended in order to prevent thick mixes. It is used at a level of 0.15 to 0.25%. It is added to mix at higher temperatures in order to minimize precipitation by calcium salts present in milk products. Sodium alginate is sensitive to high acidities often developed in some mixes and causes thickening. 

The methyl ether of cellulose has a methoxyl content which varies between 6 and 33 %. Methylcellulose can be prepared by the action of methyl chloride or methyl sulfate on cellulose that has been previously treated with alkali. Purification is accomplished by washing the reaction product with hot water. The degree of methylation can be controlled to yield products with varying viscosities. Seven viscosity types of methylcellulose are currently produced with centipoise values ranging from 10 to 4000. Methylated cellulose of low methoxy content is soluble... 

Alginate Pseudomonas aeruginosa Azotobacter vinelandii Range of viscosity types gels with Ca2 + textile printing, food applications... 

Although it was known in the years following the discovery by Cross and Bevan that a viscose type of solution could be used in the preparation of regenerated cellulose, the conversion of this solution into useful fibers was not possible until the discovery that the solution required aging until ripe. Ripening is the first part of the actual chemical decomposition of cellulose xanthate, which, if allowed to proceed unhampered, would result in gelation of the viscose solution. 

Viscosity The viscosity of an aqueous solution containing 2 g of sample per 100 g of solution is not less than 80.0% and not more than 120.0% of that stated on the label for viscosity types of 100 centipoises or less, and not less than 75.0% and not more than 140.0% of that stated on the label for viscosity types higher than 100 centipoises. 

Viscosity The apparent viscosity of a sol containing the equivalent of 2.5 g of dry sample in each 100 g of solution is not less than 80% and not more than 120% of that stated on the label or otherwise represented by the vendor. The usual range of viscosity types is between 20 and 60 centipoises. 

Apparatus Use a Brookfield Model LV series viscometer, analog or digital, or equivalent type viscometer for the determination of viscosity of aqueous solutions of cellulose gum within the range of 25 to 10,000 centipoises at 25°. Rotational viscometers of this type have spindles for use in determining the viscosity of different viscosity types of cellulose gum. The spindles and speeds for determining viscosity within different ranges are tabulated below. 

Because of its wide range of solubility, cellulose nitrate has become a popular household cement. It is a waterproof, clear, flexible adhesive for use with plastics, cloth, wood, paper, china, glass, metal, and leather. A medium or high-viscosity type cellulose nitrate is generally used with solvents that are fairly rapid in evaporation rate. A plasticizer is used to give flexibility. Several commercial grades of cellulose nitrate with characteristic properties are listed in Table III. 

Viscosity (dynamic) hydroxyethyl cellulose is available in a wide range of viscosity types e.g. Cellosize is manufactured in 11 regular viscosity grades. Hydroxyethyl cellulose grades differ principally in their aqueous solution viscosities which range from 2-20 000 mPas for a 2% w/v aqueous solution. Two types of Cellosize are produced, a WP-type, which is a normal-dissolving material, and a QP-type, which is a rapid-dispersing material. 

Natrosol 250 has a degree of substitution of 2.5 and is produced in 10 viscosity types. The suffix R denotes that Natrosol has been surface-treated with glyoxal to aid in solution preparation see Table IV. 

Viscosity (dynamic) a wide range of viscosity types are commercially available see Table V. Solutions should be prepared by gradually adding the hydroxypropyl cellulose to a vigorously stirred solvent. Increasing concentration produces solutions of increased viscosity. See also Section 11 for information on solution stability. 

Methylcellulose occurs as a white, fibrous powder or granules. It is practically odorless and tasteless. It should be labeled to indicate its viscosity type (viscosity of a 1 in 50 solution). 

The USPNF 23 describes methacrylic acid copolymer as a fully polymerized copolymer of methacrylic acid and an acrylic or methacrylic ester. Three types of copolymers, namely Type A, Type B, and Type C, are defined in the monograph. They vary in their methacrylic acid content and solution viscosity. Type C may contain suitable surface-active agents. Two additional polymers, Type A (Eudragit RE) and Type B (Eudragit RS), also referred to as ammonio methacrylate copolymers, consisting of fully polymerized copolymers of acrylic and methacrylic acid esters with a low content of quaternary ammonium groups, are also described in the USPNF 23. A further monograph for an aqueous dispersion of Type C methacrylic acid copolymer is also defined see Section 9. 

Coalescence of the droplets can only happen if it is possible to break up the thin film. This occurs if surface waves are formed or if external forces are applied. At a certain point, the thickness will fall below the critical value and coalescence occurs (17, 18). The influence of this step is given by the interfacial and surface rheological properties such as interface elasticity, interface viscosity, type of surfactant, etc. (19-25). 

Available forms Extra low- and high-viscosity types. 

Oxy/fuel burners can also be operated with propane and various fuel oils. Compared with natural gas, propane has better combustion characteristics, while oil, especially the high-viscosity type, is relatively more difficult to combust efficiently and generates additional emissions. The oil burner equipment is also more complex and expensive. 

The cellulose acetate, normally a medium viscosity type having 39 to 40 percent acetyl content, was dissolved at 5 to 10 percent solids in a solvent with slight water solubility such as cyclohex-... 

The diameters of nanofibers are important due to the fact that they directly affect conductivities of the mats. There are different reports about the effect of CPs on the diameters of nanofibers. Some of them reported higher diameters some of them reported lower diameters with increasing CP content The parameters like the method, concentration, viscosities, types of pol5miers, and conditions are also important to determine the effect of CPs on the diameters. 

The nonwoven brics used for encapsulation of webs in diCferent samples were of two types, i.e. parallel laid viseose (type A - 20 g/m ) and random laid viscose (type B -60 g/m ) (made out of waste fito) to get the absorbent cores. Nine different combinations of viscose/SAF blended carded webs (type 1-9) were prepared and those webs were sandwiched between two types of nonwoven fabric layers, i.e. total 18 absorbent cote samples were developed for study. The details of the samples are givoi in Table 1. This absorbent core was then swapped widi that of an available sample (market sample) and the product was tested using the developed core. The nomenclature of the sample (e.g. Al) implies a sandwiched absorbent core sample of falnic type A and web type 1. 

Frank et al. (2008) also define systems with solids or surfactants (type 111), or high viscosity (type IVa), or low interfacial tension (IVb), or low density difference (IVc), or formation of a stable emulsion stabilized by solids/surfactants (IVd). Successful setding of type 111 systems that have solids or surfactants present may be possible if solids are removed first by filtration and surfactants by adsorption (see Chapter 181. After the feed and solvent are pretreated, the shaker test should be repeated. Type IV systems probably require a different phase separation system, such as coalescers, centrifuges, hydrocyclones, ultrafiltration or electrotreatment and pretreatment may also be necessary. 

Halwachs et al. studied the peimeation of hydrocaibons through oil-water-oil systems. They found that the most important variables governing the peimeation rates were membrane viscosity, type and concentration of surfactant, and ionic strength of the medium. However, the permeation rates of hydrocarbons through aqueous membranes were several orders of magnitude slower than the permeation rates of phenol through hydrocarbon membranes. ... 

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