Propylene polymerization with two TiCl₄/MgCl₂ catalysts (Cat-1: Ti 0.1%; Cat-2: Ti 1.0%) showed different responses to (cyclo-C₅H₉)₂Si(OCH₃)₂ (De) addition. Cat-1 was deactivated more than Cat-2 by De. Amount of three groups of active centers producing atactic, medium isotactic and isotactic polypropylene chains were all reduced by De addition, but those of Cat-1 were reduced more. Reactivity of the isospecific active centers (k_pi) was enhanced by De, but k_pi of Cat-2 was changed more sensitively than Cat-1. The lower stereoselectivity of Cat-1 than Cat-2 are attributable to weaker De adsorption on its surface Mg, and the more sparsely dispersed Ti species on Cat-1 is responsible for weak De adsorption.

用两种TiCl ₄ / MgCl ₂催化剂（Cat-1：Ti 0.1％； Cat-2：Ti 1.0％）进行的丙烯聚合显示出对（环C ₅ H ₉）₂ Si（OCH ₃）₂（De）添加的不同响应。De对Cat-1的作用比对Cat-2的作用更大。通过添加De减少了产生无规，中等规和等规聚丙烯链的三组活性中心的数量，但是Cat-1的活性中心被进一步还原。De提高了同种异性活性中心的反应性（k _pi），但k _piCat-2的变化比Cat-1更敏感。Cat-1的立体选择性比Cat-2低，这归因于其表面Mg上的De吸附较弱，而Cat-1上Ti的分布较稀疏是De吸附较弱的原因。