Supporting Effects of Methylaluminoxane on Propene Polymerization with an Alkyltitanium Complex

摘要

Solid activators (S-MMAOs) were prepared by supporting dried modified methylaluminoxane (dried MMAO) on silica, alumina and magnesia Propene polymerization was conducted at 0°C by a chelating (diamide)dimethyltitanium complex ([ArN(CH_2)_3NAr]TiMe_2, Ar = 2,6-~iPr_2C_6H_3) combined with S-MMAOs. These heterogeneous catalytic systems conducted the polymerization without any induction period. The number-average molecular weight (M_n) of the produced polymers increased linearly against the polymerization time accompanied by narrowing molecular weight distribution (M_w/M_n), which were slightly broader than that of the corresponding homogeneous system. Living polymerization of propene proceeded irrespective of the supports for dried MMAO. The propagation rate and the M_w/M_n value depended on S-MMAO employed Among these catalytic systems, the [ArN(CH_2)_3NAr]TiMe_2-dried MMAO/SiO_2 system showed the highest propagation rate and the narrowest M_w/M_n value.