Greases physical properties

Sulfosahcyhc acid is prepared by heating 10 parts of sahcyhc acid with 50 parts of concentrated sulfuric acid, by chlorosulfonation of sahcyhc acid and subsequent hydrolysis of the acid chloride, or by sulfonation with hquid sulfur trioxide in tetrachloroethylene. It is used as an intermediate in the production of dyestuffs, grease additives, catalysts, and surfactants. It is also useful as a colorimetric reagent for ferric iron and as a reagent for albumin. Table 9 shows the physical properties of sahcyhc acid derivatives. 

The excellent chemical resistance and physical properties of PVA resins have resulted in broad industrial use. The polymer is an excellent adhesive and possesses solvent-, oil-, and grease-resistant properties matched by few other polymers. Poly(vinyl alcohol) films exhibit high tensile strength, abrasion resistance, and oxygen barrier properties which, under dry conditions, are superior to those of any other known polymer. The polymer s low surface tension provides for excellent emulsification and protective coUoid properties. 

Available in a wide range of physical states from liquids to greases, to waxes, to resins, to elastomers excellent high and moderate low temperature physical properties resistant to weathering and lubricating oils... 

The term oil and grease refers to a broad class of organic substances recovered from the sample matrices by extraction with an appropriate solvent. Such recovery, therefore, is characteristic of certain physical properties of the compounds, primarily the volatility of the compounds and their solubility in the extraction solvent. The solvent must be immiscible in water and volatile, as well as readily distilled on a water bath. Many solvents or mixed-solvent systems should be suitable for the extraction of oil and grease in aqueous and nonaqueous samples. These include petroleum ether, w-hexanc, methylene chloride, methyl ter/-butyl ether, and trichlorotrifhroroethan (freon). These solvents are listed in Table 1. 

Because of the unstable nature of ozone, the usual techniques for determination of physical properties can rarely be applied. Contact with many materials generally used in experimental work, such as rubber tubing, organic stopcock grease, and mercury, must be avoided. The quantity of pure liquid ozone must be kept small in the interests of safety. Even 1 ml. of undiluted liquid ozone can cause a disastrous explosion unless suitable precautions are taken to protect the experimenter. 

In addition to black, the elastomer may be compounded with other common fillers such as silica, clay, and asbestos. However, in general, their reinforcing properties are inferior to carbon. For certain uses, it is advantageous to compound the rubber without fillers. This gum vul-canizate has poorer physical properties than loaded stock but is better in chemical resistance. Both reinforced and gum recipes may include perfluoro greases or oils as plasticizers to soften vulcanizates without affecting appreciably chemical resistance. 

The metal phosphinates are prepared from metal salts and dialkyl or diarylphos-phosphinic acids utilizing melt or solution systems. The metal polyphosphinates are utilized as additives e.g., Cr(III) polyphosphinates thicken silicones to greases and improve their high-pressure physical properties. Chromium and titanium polyphosphinates impart antistatic properties to a wide range of plastics. 

Adhvaryu, A. S.Z. Erhan J.M. Perez. Preparation of soybean oil-based greases Effect of composition and structure on physical properties./. Agric. Food Chem. 2004, 52, 6456-6459. 

Although PW characteristics and physical properties vary considerably, the constituents of major concern are i) total dissolved solids (TDS), ii) oil and grease (O G), and iii) natural and field chemical organics [1]. In the past, the industry has targeted the removal of fiee oil and suspended solids (SS) and many cotmnercial processes are available and widely applied across the... 

Variations in the length of chains, the organic groups, and the degree of cross-linking produce silicones that vary widely in their physical properties. Silicones may be fluids (oils), greases, or even rubberlike solids. All possess a host of desirable traits resistance to temperature extremes, water repellency, antistick properties, chemical inertness, and lack of physiological activity. 

The lubricating value was determined by a Legler consistometer, which seemed to be little more than a measurement of the time required for a standard rod to sink a standard distance into a standard cup of the grease under consideration. Even though the theoretical relation between the viscosity of a fluid and its lubricating characteristics appeared to be unknown to these early workers, the importance of this physical property was most certainly appreciated. For example, consider the words of Mabery (1910) ... 

Natural rubber Low cost, good physical properties, dexterity Poor vs. oils, greases, organics. Frequently imported may be poor quality Bases, alcohols, dilute water solutions fair vs. aldehydes, ketones. 

Nitrile Low cost, excellent physical properties, dexterity Poor vs. benzene, methylene chloride, tichloroethylene, many ketones Oils, greases, aliphatic chemicals, xylene, perchloroethylene, trichloroethane fair vs. toluene... 

There are a number of requirements that a dry cleaning solvent must meet in order to be acceptable [4,7]. An acceptable dry cleaning solvent has a high affinity for grease and oil and a low affinity for fabric dyes. It must be noncorrosive to metals conunonly used in dry cleaning machinery as well as chemically and thermally stable under a variety of conditions. They must be nonflammable and sufficiently volatile to permit easy drying, and easily purified by distillation as weU as relatively safe in terms of human health and toxicity. A summary of physical properties of selected dry cleaning solvents is shown in Table 1 [8]. 

---