| 摘要 |
<p>Described herein is a triblock copolymer of the formula A-B-A wherein A is a poly(alkylene oxide) or poly(alkylene sulfide) group and B is a polymeric hydrocarbon group with a molecular weight in the range of from 1.000 to 25.000, wherein the A blocks comprise from 5 to 50 percent by weight of the copolymer, as well as polyurethane polymers prepared therefrom. Also disclosed is a process for the preparation of a functional triblock copolymer which comprises the sequential steps of: (1) polymerizing a conjugated 1,3-diene under reaction conditions sufficient to form a polydiene dianion; (2) contacting the polydiene dianion with an alkylene oxide or alkylene sulfide, in an amount and under reaction conditions sufficient to provide a block segment comprised of at least two repeat units derived from the alkylene oxide or alkylene sulfide on each end of the polymer; and (3) contacting the product of step (2) with a proton-donating compound under reaction conditions sufficient to provide a terminal hydroxyl or thiol group on each end of the copolymer.</p> |
