| 摘要 |
Conjugated hydrocarbon dienes are polymerized with lithium-sodium alloy initiator containing 0.1 to 90 mole percent sodium in a nonpolar medium at about -10 DEG C. to 100 DEG C. to yield the corresponding lithiopolydiene in which a desired high percentage of the repeating units have cis-1,4-structure. The lithiopolydienes can be used to prepare block copolymers of the ABA type in which the A units are polypivalolactone or a polymer of any other anionically polymerizable monomer and the B unit is a polydiene. The alloys can also be applied to prepare homopolydienes with high 1,4-cis structure, which are useful as vulcanizable elastomers.
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