| 摘要 |
PROBLEM TO BE SOLVED: To obtain a styrene-butadiene block copolymer synthesized by a Ti- based piano stool catalytic system. SOLUTION: This styrene-butadiene block copolymer having syndiotactic polystyrene(sPS) blocks and cis-1,4-polybutadiene(pBd) blocks can be synthesized by using a certain catalytic system when conducting the polymerization at a temperature within the range of about 0 to about 100 deg.C and a 1,3-butadiene partial pressure within the range of about 10 to about 50 mmHg. In more detail, the styrene-butadiene block copolymer 8 is a styrene-butadiene block polymer containing (a) the sPS blocks and (b) the cis-1,4-pBd blocks and the cis-1,4-pBd blocks have about <=20% of vinyl content. The sPS blocks have at least 50% syndiotactic structure content. The block copolymer contains at least 5 sPS blocks and the block copolymer has about 10,000 to about 700,000 number- average molecular weight.
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