FeCl_3-Al(i-Bu)_3-phen胶体催化剂制备方法对催化丁二烯聚合性能的影响

Effects of FeCl_3- Al(i-Bu)_3-phen Colloid System Preparation on Catalytic Activity for Butadiene Polymerization

研究了FeCl3-Al(i-Bu)3-phen胶体催化剂各组分的配比、加入顺序、陈化等制备因素对催化性能的影响.由于各组分之间形成活性位的反应是快速反应,只有按phen+FeCl3+Al(i-Bu)3的加入顺序,才能有效阻止深度还原;陈化能提高稳定和较稳定的胶体催化体系的催化活性,而对于不稳定体系,采用"单加"较适宜.陈化时加少量丁二烯,其催化活性高于不加丁二烯的,这是由于生成的丁二烯聚合物可起空间稳定作用,阻碍胶粒聚结,使其稳定在小颗粒范围内;采用适宜的[phen]∶[Fe]∶[Al]比,可制备出小而均匀的催化剂颗粒,且有利于还原生成活性位所需的Fe2+,同时得到相对稳定的胶体催化体系.

The effect of preparation factors, such as ratio and adding order of the components as well as aging, on catalytic activity have been studied. The optimum ratio of / in hydrogasoline could induce the Fe3+ reduction to Fe2+ on the surface of the catalyst particles. The optimum ratio of / makes phen and Fe2+ to form stable complex, and preventing Al(iBu)3 further reducing Fe2+ to lower valence(Fe+, Fe\+0). The catalyst particles prepared at the optimum ratio were small, even at dispersed condition. Since the reaction of conforming active site was a quick reaction, only when adding order was phen, FeCl3, then Al(iBu)3, the Fe3+ can be reduced to lower valence. So the best adding order is phen+\{FeCl3+\}Al(iBu)3. As the catalyst was stable colloidal system, its catalytic activity was hardly affected by aging for 4 h under the temperature from 15 to 20 ℃. The polymer of butadiene could strengthen the stability of colloid particles, so when aging with a few butadiene pitivity is higher then that without butadiene.