Appendix Stearic Acid

Free Fatty Acids (as stearic acid) Transfer 2 g of sample, accurately weighed, into a dry, 125-mL Erlenmeyer flask containing 50 mL of acetone, fit an air-cooled reflux condenser onto the neck of the flask, boil the mixture on a steam bath for 10 min, and cool. Filter through two layers of Whatman No. 42, or equivalent, filter paper, and wash the flask, residue, and filter with 50 mL of acetone. Add phenolphthalein TS and 5 mL of water to the filtrate, and titrate with 0.1 A sodium hydroxide. Perform a blank determination (see General Provisions) using 100 mL of acetone and 5 mL of water, and make any necessary correction. Each milliliter of 0.1 A sodium hydroxide is equivalent to 28.45 mg of stearic acid (CigH gOi). Lead Determine as directed in the Flame Atomic Absorption Spectrophotometric Method under Lead Limit Test, Appendix NIB, using a 10-g sample. 

Two fatty acids abundant in our diets are the 18-carbon saturated stearic acid and the 18-carbon unsaturated oleic acid. How is the structure of the molecule affected by the presence of a double bond Refer to Table C-1 in Appendix C for a key to atom color conventions. 

Microcellular crumbs can be used in considerable quantity along with china clay and whiting to reduce the product cost. Higher proportions of stearic acid (5-10 phr) are normally used in microcellular compounds in order to bring down the decomposition temperature of DNPT type blowing agents (see Appendix AlO). Post-cure oven stabilization of the microcellular sheets, typically at 100°C for 4 h, reduces the delayed shrinkage after cure to a minimum. 

Although Sabatier and Senderens had hydrogenated oleic acid vapor to produce stearic acid, they did not extend this work themselves. The appendix to Chapters 11 and 12 in their book describes early work to about 1916, by others who used nickel and palladium catalysts. They described the use of nickel supported on pumice, kieselguhr, asbestos, and wood charcoal. ... 

Stearic and Palmitic Acids Isolate the fatty acids as directed under Laurie Acid in the monograph for Polysorbate 20, and determine the weight of the acids. The product so obtained has an acid value between 200 and 212 when determined as directed in Method I under Acid Value, Appendix VII, and a solidification point not below 52° when determined as directed under Solidification Point, Appendix IIB. 

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