Slushing compounds

The slushing compounds are a variant of the smearing types, and possess some Row properties at room temperature so that brush marks produced during application.are reduced- Some materials contain solvent, so that they ate free-flowing as applied, but sliBien wl n the solvent evaporates. 

If the survey deals with finished petroleum products such as cutting oils, quenching oils, or slushing compounds, a separate section is added covering tests on competitive products. These data are taken from a special library card file containing such information obtained from various sources. 

Gun slushing compounds Heat insulating compounds Heat treating salts Hydrofluoric acid compound, for etching and polishing glass... 

Use of Vapor-Phase Inhibitors and Slushing Compounds. These are discussed in Chapter 17. 

An inhibitor is a chemical substance that, when added in small concentration to an environment, effectively decreases the corrosion rate. There are several classes of inhibitors, conveniently designated as follows (1) passivators, (2) organic inhibitors, including slushing compounds and pickling inhibitors, and (3) vapor-phase inhibitors. 

MACKAMIDE MO, an oleic diethanolamide, is oil soluble and water dispersible. As such, it may be blended with hydrophobic surfactants to form oil in water or even water in oil emulsions. Adding hydrophilic surfactants will aid in building viscosities. MACKAMIDE MO exhibits rust inhibition characteristics and thus is suitable for use in metalworking and slushing compounds. Viscous Amber Liquid Concentration, % 100 Color (Gardner) 8 Maximum Odor Typical... 

In recent years rotational casting methods have made the slush moulding process virtually obsolete. In these processes an amount of material equal to the weight of the finished product is poured into a mould. The mould is then closed and rotated slowly about two axes so that the paste flows easily over the cavity walls in an oven at about 200-250°C. When the compound has gelled, the moulds are cooled and the moulding removed. Compared with the slush moulding process there is no wastage of material, little flash, and more even wall thickness. Completely enclosed hollow articles such as playballs are most conveniently made. 

The flask is cooled by immersion in a slush of ice and water, and the addition compound is decomposed by adding gradually 200 g. of ice, 100 cc. of water, and 100 cc. of concentrated hydro-... 

In contrast to acidic electrolytes, chemical dissolution of a silicon electrode proceeds already at OCP in alkaline electrolytes. For cathodic potentials chemical dissolution competes with cathodic reactions, this commonly leads to a reduced dissolution rate and the formation of a slush layer under certain conditions [Pa2]. For potentials slightly anodic of OCP, electrochemical dissolution accompanies the chemical one and the dissolution rate is thereby enhanced [Pa6]. For anodic potentials above the passivation potential (PP), the formation of an anodic oxide, as in the case of acidic electrolytes, is observed. Such oxides show a much lower dissolution rate in alkaline solutions than the silicon substrate. As a result the electrode surface becomes passivated and the current density decreases to small values that correspond to the oxide etch rate. That the current density peaks at PP in Fig. 3.4 are in fact connected with the growth of a passivating oxide is proved using in situ ellipsometry [Pa2]. Passivation is independent of the type of cation. Organic compounds like hydrazin [Sul], for example, show a behavior similar to inorganic ones, like KOH [Pa8]. Because of the presence of a passivating oxide the current peak at PP is not observed for a reverse potential scan. 

B. Slush Baths. Liquid nitrogen and Dry Ice are convenient and inexpensive refrigerants. But, as shown in the examples in this chapter, a wider range of low-temperature baths is necessary for trap-to-trap fractionation of gases and for the characterization of a substance by vapor pressure measurements. A convenient constant-temperature slush bath consists of a mixture of a frozen compound in equilibrium with its liquid. The bath is made in a clean Dewar no more than... 

The sequence of operations (assuming the initial solid is not air sensitive) would be to load the sample tube with a weighed amount of reactive compound and the stirrer, to attach this tube to the tensimeter, and to pump out the air in the tensimeter. The sample tube is cooled to liquid nitrogen temperature and solvent is then condensed into the sample tube from a storage container on the vacuum line. The main valve on the tensimeter is then closed and the sample container allowed to warm so the solid may dissolve, perhaps with the aid of the stirrer. A constant temperature slush bath is next placed around the sample tube as illustrated in Fig. 9.5 and an initial pressure measurement is taken on the manometer. Next, the first alloquot of the reactive gas is transferred from a storage bulb elsewhere on the vacuum system into the calibrated bulb using the techniques outlined in Section 5.3.G (the bubbler manometer shown in Fig. 9.5 is used for the pressure determination required for this process). This gas is con-... 

Vapor pressure data are important in the identification, separation, and general manipulation of known compounds on the vacuum line and for the characterization of new compounds. This appendix was prepared with these applications in mind. It is introduced with a discussion of the use and limitations of several analytical expressions for the representation of vapor pressure data. A description of a least-squares treatment of vapor pressure data for fitting to the Antoine equation is then presented. Finally, a table of vapor pressures at convenient slush bath temperatures is presented for 479 compounds. 

Available from Alfred Bader Chemicals, Aldrich Chemical Company, Inc., 940 West St. Paul Ave., Milwaukee, WI 53233. Prior to use the compound should be purified on the vacuum line by fractional condensation at -45° (chlorobenzene slush) to eliminate any dimethylamine formed through possible exposure to atmospheric moisture. 

PVC plastisol compounds can be manipulated into shapes, or applied to fabrics in the ungelled state by either simple flow techniques or by very low pressure processes. The main techniques are spreading, dipping, spraying and rotational and slush moulding. 

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