Spreading characteristics

Od-in-water based hairdressings offer good spreading characteristics, have a less greasy feel, and are more easdy rinsed than water-in-od forms. Mineral od is found in these products, although natural and synthetic ods have been used. The typical od-in-water emulsifiers are used in preparing these emulsions. 

Column dispersity (band spreading) causes the measured molecular weight distribution to be broader than the true molecular weight distribution (Fig. 3.5). Because Zorbax PSM columns exhibit very low band-spreading characteristics, these columns have historically provided better molecular weight distribution accuracy than many gel-type columns. 

The relationship of thermodynamic functions of selective bonding of Hb to a series of carboxylic CP in the variation of the degree of ionization of carboxylic groups is expressed by the effect of enthalpy-entropy compensation (Fig. 18). The compensation effect of enthalpy and entropy components is the most wide-spread characteristic of many reactions in aqueous solutions for systems with a cooperative change in structure [78],... 

Dihexyl sulfosuccinate is used to improve the wetting and spreading characteristics of water-soluble pesticide sprays. In liquid fertilizers, insecticides, and fungicides, dioctyl sulfosuccinate will increase their penetrating ability. 

Flame spread characteristics of product first ignited... 

In the case of oil spills on the seas, these considerations become very important. The treatment of such pollutant systems requires knowledge of the state of the oil. The thickness of the oil layer will be dependent on the spreading characteristics. The effect on ecology (such as birds and plants) will depend on the spreading characteristics. 

The test method described in ASTM E 162 also evaluates opposed-flow flame spread characteristics of a product, and is referred to in regulations that pertain to various modes of transportation. 

Stickers increase the adherence of the chemical to the treated surface, thus increasing its persistence, particnlarly under adverse weather conditions. Many spreaders also possess wetting and spreading characteristics. 

Boylan, J.C. Rheological estimation of the spreading characteristics of pharmaceutical semisolids. J. Pharm. Sci. 1967, 56, 1164-1169. 

Isopropyl palmitate is a nongreasy emollient with good spreading characteristics, used in topical pharmaceutical formulations and cosmetics such as bath oils creams lotions make-up hair care products deodorants lip products suntan preparations and pressed powders see Table I. 

Spreading characteristics from the mesoscopic transport modei... 

To quantify the spreading characteristics, we examined the thickness-dependent diffusion coefficient D h), extracted from the SME via two methods. The first method utilizes the spreading data at constant height (isoheight), while the second method utilizes the entire... 

Min, B.G. Choi, J.W. Brown, H.R. Yoon, D.Y. O Connor, T.M. Jhon, M.S. Spreading characteristics of thin liquid films of perfiuoropolyalkyl-ethers on solid surfaces eff ects of chain-end functionality and humidity. Trib. Lett. 1995, 1, 225-232. 

Fractionation. The melting and spreading characteristics of butter can be altered by fractional crystallization, i.e. controlled crystallization of molten fat or crystallization from a solution of fat in an organic solvent (e.g. ethanol or acetone). Cleaner, sharper fractionation is obtained in the latter but solvents may not be acceptable for use with foods. The crystals formed may... 

Hydrocarbon aerosol hair sprays contain an alcohol-hydrocarbon solvent-propellant system, a synthetic polymeric resin, a base to neutralize the resin if it is a carboxylic acid-containing resin, plasticizer(s), fragrance, and, in some cases, surfactant(s) to improve the spreading characteristics of the polymer. Most of the new low-VOC aerosol hairsprays contain alcohol-water as the solvent system and dimethyl ether as the propellant. Together the alcohol-dimethyl ether content must be below 55% (54.5%). For cost considerations, dimethyl ether is the propellant of choice, although Hydrofluorocarbon 152-A is exempt as a VOC and provides acceptable, but expensive formulations with previously used resins [54]. In Europe and other parts of the world, there are no VOC limits, and hydrocarbon-alcohol systems with virtually no water are widely used. 

The ability of the resin to spread over the hair surface is largely a function of the resin and is determined by its surface tension and the viscosity of the system however, spreading characteristics of resins can be somewhat improved by adding surfactants [58]. Nonionic or cationic surfactants are generally preferable to anionics for this purpose. 

Excellent spreading characteristics Non-toxic and chemically inert Effective at high temperatures in white-water systems Highly effective at lower dosages Environment-friendly... 

Reasons for nse good spreading characteristics, improvement of prodnction rate, redaction of adhesion between surface of equipment and plastic materials in contact (mostly during their production)... 

Part 5 is relevant to floor coverings since these are required to have a surface with low flame spread characteristics and are tested in accordance with Resolution A.653(16). This defines a method of determining surface heat spread in a vertical orientation under a heat flux of 49.5 kWm" at the initial part of the sample length reducing to 1.5kWm- after 740 mm. Thus carpet fabrics must have higher flame resistance than normally expected for such a horizontally orientated textile. Consequently, flame retarded wool (e.g. Zirpro -treated wool see Chapter 8) will feature as an important fibre in appropriate woven or tufted stractures which combine both the necessary aesthetic and technical requirements. 

It is seen from Table 6.7 that, without exception, in a wide range of commercially available fire retardant polymers the incorporation of fire retardant additives into the formulation produces distinct improvements in LOI values and flammability and flame spread characteristics of the polymers listed. 

Diluents. These are generally incorporated to reduce the viseosity of the freshly mixed adhesive to offset the effect of the filler. This may be required to improve handling and spreading characteristics or to allow filler additions which tend to reduce cost. Other properties of the fresh and hardened adhesive can be affected by the use of diluents, for example pot life, flexibility and glass transition temperature. If the diluent is non-reactive, such as solvents which remain in the cured system, the net result is a deterioration of chemical and mechanical properties such as increased shrinkage and reduced adhesion. Reactive diluents containing epoxy compounds are capable of combining chemically with the resin/hardener system. 

Ycfor PE, PMMA and PS are in agreement with the values measured by Dann (7) (see Table 2). Using the adhesion properties shown in Table 5 and the relationships listed in Table 1, we can determine the work of adhesion and spreading characteristics of polymer-polymer systems. 

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