摘要
以２，２－二异丁基－１，３－二甲氧基－丙烷（ＤＩＢＤＭＰ）为内给电子化合物制备了一种新的负载型催化剂，该催化剂在无需添加外给电子化合物的情况下即可获得高等规度的聚丙烯．考察了ＤＩＢＤＭＰ加入量、Ａｌ／Ｔｉ比和聚合温度对聚合反应的影响．结果表明，当ＤＩＢＤＭＰ／Ｍｇ超过０．２时，催化活性和产物的等规度趋于稳定，ＡｌＥｔ３浓度对聚合的影响可用Ｌａｎｇｍｉｕｒ－Ｈｉｎｓｈｅｌｗｏｏｄ竞争吸附模型来解释．同传统负载型催化剂相比，ＡｌＥｔ３对此催化剂的活性和聚丙烯等规度的影响要小得多，说明ＤＩＢＤＭＰ被不易ＡｌＥｔ３移走．常压淤浆聚合时。
A novel supported catalyst for propylene polymerization was prepared by using 2,2 diisobutyl 1,3 dimethoxyl propane(DIBDMP) as internal electron donor.The results of extraction and 13 C NMR showed that highly isotactic PP was obtained in the absence of external electron donor. The effects of the amount of DIBDMP added,Al/Ti and temperature on the polymerization were investigated.The activity and isatactic index tend to be a constant when added DIBDMP is large enough.The dependence of polymerization rate on the concentration of AlEt 3 can be explained by Langmuir Hinshelwood competing adsorption model.Compared with conventional supported catalysts,the effect of Al/Ti on this catalysts is much less,which indicates that DIBDMP is difficult to be removed by AlEt 3.In slurry polymerization at atmospheric pressure,the polymerization obeys Arrehnius equation in the range of 30～50℃.
基金
国家自然科学基金
关键词
聚丙烯
催化剂
给电子化合物
polyproplyene
ziegler natta catalyst
electron donor
