The reactivity of sodium borohydride with various species as characterized by adiabatic calorimetry.

The reactivity of sodium borohydride in the presence of other species has been examined by adiabatic calorimetry. In combination with water, sodium borohydride exhibits an exotherm at room temperature accompanied by generation of gas (presumed to be hydrogen). Addition of potassium hydroxide to a sodium borohydride-water mixture is found to stabilize the solution and require a higher temperature for reaction to occur. However, if iron oxide is also included, reaction takes place near room temperature. Very rapid reaction was found when a metal chloride was brought in contact with a solution containing sodium borohydride, water, and potassium hydroxide. When sodium borohydride was added to an oxygenated hydrocarbon, reaction at room temperature also took place, but to a more limited extent. Peak temperatures above 200 degrees C and maximum pressures in excess of 2000 psia were observed in most cases. Kinetics extracted from the calorimetry data are presented for some of the sodium borohydride combinations.

Kinetics of acid-catalyzed cleavage of cumene hydroperoxide.

The cleavage of cumene hydroperoxide, in the presence of sulfuric acid, to form phenol and acetone has been examined by adiabatic calorimetry. As expected, acid can catalyze cumene hydroperoxide reaction at temperatures below that of thermally-induced decomposition. At elevated acid concentrations, reactivity is also observed at or below room temperature. The exhibited reactivity behavior is complex and is significantly affected by the presence of other species (including the products). Several reaction models have been explored to explain the behavior and these are discussed.