Cooling additives

Cooling is most effectively accompHshed with a tandem arrangement of two extmders, as shown ia Figure 12, whereia the first extmder ensures complete dissolution of the blowiag ageat, and the second extmder is operated at slow speed for optimum cooling. Additional information on extmsion of foams is contaiaed ia Reference 28 (see FoAAffiD plastics Insulation, thermal). 

A solution of 2-chloro-Ar-(2-hydroxy-4-tolyl)-5-nitropyridine-3-carboxamide (6.3 g, 20 mmol) in pyridine (100 mL) was heated under argon at 90°C for 2.5 h and then cooled. Addition of H20 precipitated the crude product, which was collected and washed successively with hot H20, EtOH and Et20 yield 4.08 g (75%) mp 285-288JC. 

A mixture of 2-methylpyrido[3,4-d]pyrimidine-4-one 261 (1 mmol), benzylamine (3 mmol), HMDS 2 (3 mmol), and (NH4)2S04 (0.1 mmol) is heated under reflux for 4—5 h. After cooling, addition of 10 mL ethanol, and evaporation, the residue is recrystallized from water or aqueous methanol to give 97% 2-methyl-4-benzyla-minopyrido[3,4-d]pyrimidine 262, m.p. 156-160°C [74] (Scheme 4.60). 

Addition of the aluminate (0.5 g) to pyridine (50 ml) must be effected very slowly with cooling. Addition of 1 g portions may cause a highly exothermic reaction. 

Firedamp-proof Detonators. Firedamp-proof detonators have net received tht attention that firedamp-proof expls have, possibly because the expln of the, detonator is lost in the immediately succeeding expln of the main charge. Treatment of the detonator charge in caps follows similar lines to treatment of Dynamites in the addition of cooling additives, such as salts or wax (Ref 1), BuOAc (butyl acetate) (Ref 2), or poly car boxy lie acids, oxygenated poly carboxylic acids, halogen substituted poly carboxylic and oxygenated polycarboxylic acids, and the neutral and acid salts of these (Ref 4)... 

The tangential stresses at the inner side of a cylindrical vessel can be substantially reduced if two or more cylinders are shrunk one onto the other. Shrunk vessels are manufactured by heating the outer cylinder before combining the both parts. The maximum heating temperature is around 500°C. In special cases it is usual to cool additionally the inner cylinder. Another method is to press two or more conical parts mechanically together. All parts used in shrunk constructions must be exactly fabricated and controlled. 

C, under pressure in a PTFE-coated vessel. Cooling, addition of 6-chlorop-urine as the internal stan-... 

During fabrication using the MWR process, two forces act on the plastic injection (longitudinal) and rotation (hoop). The targeted balanced orientation is a result of those forces. As the product wall cools, additional high-magnitude, cross-laminated orientation is developed frozen in and throughout the wall thickness. Orientation on molecular... 

An alcoholic solution of the trianliydrotetrakis-compound with hydrochloric acid does not give so ]>ure a product of the tetra-com-pound. The tri-body may be converted into the tetra-derivative also by heating the former at ioo to 200 C. for fifteen minutes. Water is evolved, and witcu decomposition ceases the mass is cooled. Addition of etlior causes this to erystallise, and cold alcohol removes only a little soluble matter. The residue on crystallising several times yields pure tetra-auhydrotetrakisdiphcnylsilieanediol, which forms well-defined, almost rectangular plates, when deposited from ethyl acetate at the ordinary temperature. These have been measured and the results are recorded in Table XL of Appendix. 

Such a solution will be difficult to handle because crystallization will occur during filtration. If 20 ml of the solvent are used, all the solute will remain in solution at 20°. Therefore water can be added after filtration until cloudiness just appears, and the solution is then allowed to cool. Addition of 80-85 ml of water will cause the crystallization of about 8 g of acetanilide. If the amount of solid is 5 g or over and the solvent is water, solution is effected in a beaker or Erlenmeyer flask. The water is heated to nearly boiling and then the solid is added and stirred with a rod to break the lumps the heating is resumed until solution is complete. If the solvent is inflammable, toxic, or volatile, solution is effected in a flask provided with a reflux condenser as shown in Figure 4. The flask is heated by means of a water bath or steam bath. If a water bath is used, care should be taken to have a small flame and to make sure that the cork by which the condenser is attached to the flask does not leak and that the cold water circulates through the condenser. 

From pilot plant results, determine variables—agitator speed, cooling/addition rate, seed amount and timing, effect of point of addition—which contribute to differences in chemical purity and physical attributes. 

Wolfiamite NaOH 1 1.0-1.5 100-150°C Atmospheric After cooling, addition of water to... 

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