Abstract: A method for removing carbonaceous impurity from zinc oxide by contacting a water slurry of contaminated zinc oxide with oxygen in a reactor at reaction conditions sufficient to produce oxide products of the carbon contaminants and passing the reactor effluent through a filter to collect solid zinc oxide while passing the oxides of carbon through the filter. In a preferred embodiment, contaminated zinc oxide separated from the reaction product in the preparation of terephthalic acid from benzoic acid using zinc benzoate catalyst is subjected to treatment for removal of carbonaceous contaminants before being recycled to reaction with molten benzoic acid to produce zinc benzoate catalyst used in the reaction.

Abstract: An alpha-methylstyrene polymerization reaction mass is cooled by including therein a component which is readily vaporizable under the conditions of polymerization thereby to remove undesirable or excess heat, thus controlling the reaction temperature to a desired value. In one embodiment a living polymer is produced followed by addition of a second monomer to the living polymer still in solution followed by polymerization onto the living polymer, forming a living block copolymer which is coupled with a linking agent.