| 摘要 |
Pure syndiotactic 1,2-polybutadiene is a thermoplastic resin which has double bonds attached in an alternating fashion to its polymeric backbone. Films, fibers and molded articles can be made utilizing syndiotactic 1,2-polybutadiene. It can also be blended into rubbers and cocured therewith. Syndiotactic 1,2-polybutadiene can be made by solution, emulsion or suspension polymerization. It typically has a melting point which is within the range of about 195.degree.C to about 215.degree.C. However, it is often desirable for the syndiotactic 1,2-polybutadiene to have a melting point of less than about 195.degree.C. This invention discloses a process for preparing syndiotactic 1,2-polybutadiene having a melting point of less than about 195.degree.C which comprises: polymerizing 1,3-butadiene monomer in an aqueous medium in the presence of (1) a catalyst composition which is made by reacting (a) at least one cobalt compound (b) at least one organoaluminum compound, and (c) at least one conjugated diene; (2) carbon disulfide; and (3) at least one modifier selected from the group consisting of (a) 4-(alkylamino)benzaldehydes, (b) 4-(dialkylamino)benzaldehydes, (c) 2,4-di-(alkoxy)benzaldehydes, (d) 2,6-di-(alkoxy)benzaldehydes, (e) 2,4,6-tri-(alkoxy)benzaldehydes, and (f) 4-(1-azacycloalkyl)benzaldehydes.
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