Effect of the particle size of the TiCl4-Ali-Bu3 catalyst on the contribution from mono- and bimetallic active sites to the polymerization of isoprene
作者:V. Z. Mingaleev
DOI:10.1134/s0023158416010109
日期:2016.1
characterized by low activity and low 1,4-cis specificity in the polymerization of isoprene. “Colloid” active sites have a bimetallic structure and produce polyisoprene at a high rate; the concentration of 1,4-cis units in the resulting polyisoprene is as high as 97%. The contribution from the colloid active sites to the polymerization of isoprene increases with the particle size of ß-TiCl3.
SS-的TiCl的配位不饱和表面之间的相互作用3颗粒在的TiCl和液相4 -Al我-Bu 3催化剂是负责最终粒度和异戊二烯聚合的规律性。在催化剂形成和再活化的过程中,催化剂活性和聚异戊二烯的分子特性与催化剂粒径的相关性指示了两组活性位点的出现。“表面”活性位点对应于单金属Cossee模型,并且具有低活性和低1,4-顺式的特征异戊二烯聚合反应的特异性。“胶体”活性部位具有双金属结构,并以高速率产生聚异戊二烯。所得聚异戊二烯中1,4-顺式单元的浓度高达97%。从胶体活性位点以与SS-的TiCl的粒径增加的异戊二烯聚合的贡献3。