Abstract: A process for activating double metal cyanide catalysts is disclosed. A polyol starter or starter/catalyst mixture is heated under vacuum under conditions effective to achieve improved stripping compared with that which can be achieved through conventional vacuum stripping. Coupling vacuum stripping with inert gas sparging or stripping in the presence of an organic solvent gives a starter/catalyst mixture that activates rapidly in an epoxide polymerization process. Rapid activation makes process start-ups reliable and reduces cycle time. The process gives polyols with lower viscosity, lower polydispersity, and lower unsaturation for better polyurethanes.

Abstract: Polyurethane elastomers exhibiting improved green strength while maintaining short demold times are prepared from ultra-low unsaturation polyoxypropylene polyols containing up to 20 weight percent internal random oxyethylene moieties. The elastomers adsorb less than 10 weight percent water at 0.degree. C. The internal polyoxyethylene moiety-containing polyoxypropylene polyols may be used to prepare ultra-low unsaturation polyoxyethylene capped polyols which are haze-free and which may be used to prepare haze-free 4,4'-MDI prepolymers. Multidisperse blends of monodisperse internal oxyethylene moiety-containing polyoxypropylene polyols of ultra-low unsaturation provide yet further improvements in elastomer processing.

Abstract: The process of regenerating a stable organic soluble molybdenum-containing catalyst suitable for epoxidation of olefins with a hydroperoxide which comprises thermally precipitating and separating a molybdenum-containing solid obtained from a spent catalyst stream derived from a molybdenum catalyzed epoxidation of an olefin and solubilizing the precipitated solid by contacting with a liquid composition comprising a peroxy compound, a monohydroxy alcohol, optionally a polyhydroxy alcohol, and an organic dicarboxylic acid present in an amount of at least about 0.2 parts, by weight, of molybdenum contained in said solid.

Abstract: Production of molybdenum-containing stable catalyst solutions especially adapted for use in the epoxidation of olefinic compounds with an organic hydroperoxide by reaction of molybdenum metal with a peroxy compound and an organic dicarboxylic acid in the presence of monohydroxy alcohol is provided.