摘要 |
Unique, well defined polyethers containing both hydroxyl-functionality and unsaturation-functionality are prepared by oxyalkylating an unsaturated monomer having at least one oxyalkylatable hydrogen in the presence of an effective amount of a double metal cyanide complex catalyst, optionally, when necessary, in the presence of a free radical polymerization inhibitor. The resulting polyethers are eminently suitable for such uses as polymer polyol stabilizers or stabilizer precursors, and both in situ and ex situ impact modifiers for thermoplastics. Unique, well defined macromonomers containing hydroxyl-functionality, unsaturation-functionality, and polyoxyalkylene segments are prepared by oxyalkylating an unsaturated initiator molecule having at least one oxyalkylatable hydrogen in the presence of an effective amount of a double metal cyanide complex catalyst, optionally, when necessary, in the presence of a free radical polymerization inhibitor. The resulting unsaturated macromonomers are eminently suitable for such uses as copolymerization with ethylenically unsaturated monomers containing carboxylic acid-based groups such as acrylic acid to form effective superplasticizers and water reducers for cement and concrete applications. |