Abstract: In the direct oxidation of isobutane with molecular oxygen at moderate isobutane conversion levels (up to about 20%) in a reaction mixture maintained at a pressure greater than its critical pressure and at a temperature in the range from about 140.degree. C. to 170.degree. C., the selectivity of the isobutane conversion to tertiary-butyl hydroperoxide is enhanced with only minimal impact on the reaction rate by controlling the oxygen concentration in the reaction mixture at a level below about 0.1%M.

Abstract: A process for the removal of impurities from solvents utilized in a cyclic process for the production of block copolymers is provided which comprises separation of block copolymers from their polymerization solvent, the separated solvent having a stated temperature, and hydrotreatment of the solvent with a heterogeneous hydrogenation catalyst at a weight hour space velocity greater than about two, whereby the undesirable contaminents are reduced, and recycling the hydrotreated solvent to the polymerization reactor.

Abstract: A cyclic process is provided for the polymerization and hydrogenation of certain polymers wherein the monomer is anionically polymerized in solution, the living polymers then being terminated by the use of a proton donor, after which the polymer is subjected to catalytic hydrogenation wherein the catalyst is optionally activated with certain polar compounds after which the polymer is coagulated and heated to remove any residual terminator and activator and the solvent is fractionally distilled to recover and recycle the solvent without contamination from the substantially higher boiling terminator and optional activator.

Abstract: The process of hydrogenating olefin compounds utilizing certain hydrogenation catalysts can be interrupted or halted by the addition to the reaction mixture of an organometallic reducing agent. Hydrogenation can be resumed by subsequent addition of an alcohol or other compound capable of reacting with the reducing agent.