Melting point sources

Selected Examples of Cyclic Hydrocarbons Found in Crude Oils (MW = Molecular Weight, NBP = Boiling Point at 760 mm Hg, MP = Melting Point) [Source of Data Reference 63]... 

The thennal evaporation source was the earliest used to produce metal clusters in the gas phase [H, 12 and 13], mostly for clusters of the alkalis and other low melting point materials. In this technique, a bulk sample is simply... 

Fa.ts nd Oils. Eats and oils from rendering animal and fish offal and vegetable oilseeds provide nutritional by-products used as a source of energy, unsaturated fatty acids, and palatabiHty enhancement. Eats influence the texture in finished pet foods. The use and price of the various melting point fats is deterrnined by the type and appearance of the desired finished food appearance. 

National Institute of Standards and Technology (NIST). The NIST is the source of many of the standards used in chemical and physical analyses in the United States and throughout the world. The standards prepared and distributed by the NIST are used to caUbrate measurement systems and to provide a central basis for uniformity and accuracy of measurement. At present, over 1200 Standard Reference Materials (SRMs) are available and are described by the NIST (15). Included are many steels, nonferrous alloys, high purity metals, primary standards for use in volumetric analysis, microchemical standards, clinical laboratory standards, biological material certified for trace elements, environmental standards, trace element standards, ion-activity standards (for pH and ion-selective electrodes), freezing and melting point standards, colorimetry standards, optical standards, radioactivity standards, particle-size standards, and density standards. Certificates are issued with the standard reference materials showing values for the parameters that have been determined. 

Thermoplastic Fibers. The thermoplastic fibers, eg, polyester and nylon, are considered less flammable than natural fibers. They possess a relatively low melting point furthermore, the melt drips rather than remaining to propagate the flame when the source of ignition is removed. Most common synthetic fibers have low melting points. Reported values for polyester and nylon are 255—290°C and 210—260°C, respectively. 

Strontium Oxide, Hydroxide, and Peroxide. Strontium oxide, SrO, is a white powder that has a specific gravity of 4.7 and a melting point of 2430°C. It is made by heating strontium carbonate with carbon in an electric furnace, or by heating celestite with carbon and treating the sulfide formed with caustic soda and then calcining the product (10). It reacts with water to form strontium hydroxide [18480-07-4] and is used as the source of strontium peroxide [1314-18-7],... 

Values extracted and in some cases rounded off from those cited in Rabinovich (ed.), Theimophysical Propeities of Neon, Ai gon, Krypton and Xenon, Standards Press, Moscow, 1976. m = melting point c = critical point. The notation 6.654.-4 signifies 6.654 X 10 . This source contains values for the compressed state up to 1000 bar, etc. This book was published in English translation by Hemisphere, New York 1988 (604 pp.). 

In the case of crystalline polymers better results are obtained using an amorphous density which can be extrapolated from data above the melting point, or from other sources. In the case of polyethylene the apparent amorphous density is in the range 0.84-0.86 at 25°C. This gives a calculated value of about 8.1 for the solubility parameter which is still slightly higher than observed values obtained by swelling experiments. 

In order that there might be no doubt as to the identity of the synthetical product, it was converted into the nitrosochloride, C,oH, 0, NOCl (melting-point 122°), and phenylurethane, Cj Hj-O. CO. NH. C H (melting-point 113°), and these were compared with specimens made from ordinary terpineol, with the result that the preparations obtained from the two sources were found to be absolutely identical. 

Valucs or densities, and of boiling and melting points, obtained from various sources do not always correspond. 

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