A novel SiO2-supported inorganic and organic hybrid chromium-based catalyst for ethylene polymerization
A novel SiO2-supported inorganic and organic hybrid chromium-based catalyst for ethylene polymerization
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DOI：
10.1016/j.molcata.2012.01.021
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发表时间：
2012-06
影响因子：
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通讯作者：
Shiliang Zhang;Qi Dong;R. Cheng;Xuelian He;Quntao Wang;Yan Tang;Yongling Yu;Kan Xie;Jianwen Da;Bo-ping Liu
中科院分区：
文献类型：
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作者：
Shiliang Zhang;Qi Dong;R. Cheng;Xuelian He;Quntao Wang;Yan Tang;Yongling Yu;Kan Xie;Jianwen Da;Bo-ping Liu
本工作利用Phillips催化剂中残留的表面羟基进一步负载双(三苯基甲硅烷基)铬酸酯(BC)，制备了一种新型的用于乙烯和乙烯/1-己烯聚合的SiO2负载杂化铬基催化剂，以充分发挥无机Phillips和有机S-2这两种重要铬基催化剂的优点。 催化剂。通过对催化剂的表征、聚合行为和聚合物微观结构的研究，对助催化剂、BC添加量、焙烧温度、总铬负载量、聚合温度、压力和氢气等几个重要因素进行了系统研究。 BC的适宜添加量为CrBC≤0.25wt%。适宜的焙烧温度和总铬含量分别≤600℃和≤0.5wt%。随着CrBC相对添加量从0增加到20、50、80和100wt%（对应Phillips的HCat-1、HCat-2、HCat-3和S-2催化剂），上述催化剂的共聚能力均呈现下降趋势。通过比较不同的铬催化剂，HCat-2催化剂表现出比S-2催化剂更高的活性，并且其聚合物比Phillips催化剂获得的聚合物具有更高的平均分子量（MW）。 HCat-2催化剂具有良好的平衡性能，主要包括活性、聚合物的分子量和共聚能力。
In this work, a novel SiO2-supported hybrid chromium-based catalyst for ethylene and ethylene/1-hexene polymerization was prepared by using the residual surface hydroxyl groups in Phillips catalyst to further support bis(triphenysilyl) chromate (BC) in order to get the merits from two important chromium-based catalysts namely inorganic Phillips and organic S-2 catalysts. By characterization of the catalysts, investigation of the polymerization behavior and the microstructures of polymers, several vital factors such as cocatalyst, the addition amount of BC, calcination temperature, total chromium loading, polymerization temperature, pressure and hydrogen were systematically investigated. The proper addition weight amount of BC was CrBC≤0.25wt%. The suitable calcination temperature and total chromium loading were ≤600°C and ≤0.5wt%, respectively. With increasing the relative addition amount of CrBCfrom 0 to 20, 50, 80 and 100wt% (corresponding from Phillips to HCat-1, HCat-2, HCat-3 and S-2 catalysts), the copolymerization abilities of the above catalysts showed a decreasing tendency. By comparing different chromium catalysts, HCat-2 catalyst showed higher activity than S-2 catalyst and its polymer had higher average molecular weight (MW) than that obtained from Phillips catalyst. HCat-2 catalyst got well-balanced properties mainly including activity, MW of polymers and copolymerization ability.