preparation of aryloxy-凯发网

in this study, a series of aryloxy-aluminoxanes originated directly from the hydrolysis of reaction products of alme_3 and phenols were synthesized, which could serve as effective polymer-retarding activators for the iron-catalyzed ethylene oligomerization.the molar ratios of [phoh]/[alme_3] and [h_2o]/[al] during the preparation were explored and their impacts on the oligomerization activity and product distribution were discussed. to obtain the effective activators with good polymer-retarding effect and relatively high activity, the optimized conditions were proposed to be [phoh]/[alme_3] = 0.5 and [h_2o]/[al] = 0.7. various aluminoxanes with different[―oh] sources confirmed the importance of using phenols in preparing the effective polymer-retarding activators. by utilizing these aryloxy-aluminoxanes, the mass fraction of polymers in the total products could be reduced to lower than 1.0 wt%, which is much lower than that of the mao-activated systems(> 30 wt%). this is a potential benefit for the industrial application of the iron-catalyzed oligomerization process.