Petroleum distillate color change

Color Change. Tables I through IV summarize the color change data, obtained by comparison with an untreated/unexposed control sample, for the dyed cotton and wool fabrics exposed to CC14, dichlorvos, petroleum distillate, and boric acid respectively. Each table reports the total color difference at 4, 8, and 160 weeks duration after initial treatment. Also reported is a visual description of the perceived color change from the untreated control after 160 weeks. 

Another test determines density and specific gravity by means of a digital densimeter (ASTM D-4052, IP 365). In the test, a small volume (approximately 0.7 ml) of liquid sample is introduced into an oscillating sample tube and the change in oscillating frequency caused by the change in the mass of the tube is used in conjunction with calibration data to determine the density of the sample. The test is usually applied to petroleum, petroleum distillates, and petroleum products that are liquids at temperatures between 15 and 35°C (59-95°F) that have vapor pressures below 600 mmHg and viscosities below about 15,000 cSt at the temperature of test. However, the method should not be applied to samples so dark in color that the absence of air bubbles in the sample cell cannot be established with certainty. 

Asphalt Asphalt is a natural occurring mineral or as the residue from the distillation of asphaltic petroleum. It is less brittle and has better resistance to sunlight and temperature changes than coal tar enamel. Its water resistance is good but less than for coal tar enamel. It is not resistant to solvents or oils. It may crack at low temperatures and age at elevated ones. Like coal tar enamels, it is primarily black in color and difficult to overcoat with other materials. Its main use is for the in-situ coating of roofs or aboveground steel structures. 

Early refiners utilized simple batch distillation to prepare kerosenes and lubricating oils. As the demand for these materials expanded and new crude oils were found, certain desirable and undesirable characteristics became apparent. Crude oils were selected from which products possessing desirable characteristics could be distilled—for example, oxidation stability, low smoke tendency, low carbon-forming tendency, small viscosity change with change in temperature (high viscosity index), light color, and attractive appearance were more likely to be found in petroleum of the paraffinic or Pennsylvania type. 

This is the solid residue left when turpentine is distilled for the preparation of oil of turpentine. It consists essentially of resin acids and their oxidation products and forms brittle, translucent masses with a peculiar resinous odour and a colour varying from pale yellow to dark brown D = 1 05-1 085. It is readily soluble in alcohol (1 part in 10 parts of 70% alcohol) and dissolves also in methyl or amyl alcohol, ether, acetone, benzene, chloroform, carbon disulphide or oil of turpentine in petroleum ether it is not completely soluble. It is easily and completely saponified by caustic soda solution. Addition of a drop of concentrated sulphuric add to a solution of a small quantity of colophony in acetic anhydride produces an intense violet-red or purple coloration, soon changing to yellowish-brown. Different types or grades of colophony are sold, distinguished mainly by the colour and origin. 

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