Isomeric 1-(fluoren-9-yl)-2-(2-methyl-5, 6-dihydrocyclopenta [f]-1 H-indenyl) ethanes 1a,b and C 1-symmetric metallocenes, viz., rac-1-(η5-fluoren-9-yl)-2-(2-methyl-5, 6-dihydrocyclopenta [f]-η5-inden-1-yl) ethanezirconium dichloride (9) and rac-1-(η5-fluoren-9-yl)- 2-(2-methyl-5, 6-dihydrocyclopenta [f]η5-inden-1-yl)ethanehafnium dichloride (10), with these ligands were synthesized by modified procedures. The structures of compounds 1b (two crystalline modifications) and 10 were established by X-ray diffraction analysis. The synthesis of polypropylene (PP) in bulk was studied in the presence of polymethylalumoxane-activated metallocenes 9 and 10 in the temperature range of 30–70°C. It was demonstrated that triisobutylaluminum can be used as a cocatalyst. In this case, the molecular weight of PP increases by a factor of ∼2. An increase in the reaction temperature leads to an increase in stereoregularity and crystallinity of PP. The polymer synthesized at high temperatures crystallizes in the γ form. The resulting PP is characterized by a wide range of properties from rigid crystalline thermoplastic to amorphous elastomeric. Samples, which have a high molecular weight and moderate isotacticity, exhibit high elastomeric and durability properties.
异构 1-(
芴-9-基)-2-(2-甲基-5, 6-二氢环戊并[f]-1 H-
茚基)
乙烷 1a, b 和 C 1 对称茂
金属,即、通过改进的程序合成了带有这些
配体的 rac-1-(η5-
芴-9-基)-2-(2-甲基-5, 6-二氢环戊并[f]-η5-
茚-1-基)
乙烷二
氯化
锆(9)和 rac-1-(η5-
芴-9-基)-2-(2-甲基-5, 6-二氢环戊并[f]-η5-
茚-1-基)
乙烷二
氯化铪(10)。通过 X 射线衍射分析,确定了化合物 1b(两种晶体修饰)和 10 的结构。在聚甲基铝氧烷活化茂
金属 9 和 10 的存在下,在 30-70°C 的温度范围内研究了聚
丙烯(PP)的合成。结果表明,
三异丁基铝可用作助催化剂。在这种情况下,聚
丙烯的分子量增加了 ∼ 2 倍。反应温度升高会导致 PP 的立体规整度和结晶度增加。在高温下合成的聚合物以 γ 形式结晶。生成的聚
丙烯具有从刚性结晶热塑性塑料到无定形弹性体等多种特性。具有高分子量和中等同素异形性的样品具有较高的弹性和耐久性能。