ブタジエンゴムとイソプレンゴムの最近の技術動向 Recent Trends of Polybutadiene and Polyisoprene
High cis-polybutadiene (BR) and high cis-polyisoprene (IR) are widely used in the industrial field such as materials for tire.<br>High cis-BRs prepared from Ziegler-type catalyst system are effective to take a cis configuration in high levels, however, the molecular weight distributions (Mw/Mn) of obtained BRs are fairly broad. BR having both narrow Mw/Mn and high cis configuration levels are desirable for the purpose of better abrasion resistance, higher resilience and lower heat build-up, and so on.<br>On the other hand, 1, 4-cis selectivity of IR synthesized with Li-, Ti- and Nd-based catalysts are still lower than NR, and their physical properties, e.g., Green strength, tensile strength or tear strength, are not satisfactory compared to NR.<br>Recently, several kinds of catalysis systems were investigated to achieve simultaneous control of both molecular weight distribution and cis-1, 4 specificity in the polymerization of both butadiene and isoprene. In this paper, recent trends in research on the polymerization of cis-1, 4 polybutadiene and cis-1, 4-polyisoprene are reviewed.
日本ゴム協會誌 78(2), 42-45, 2005-02-15