新型内给电子体聚丙烯催化剂小试研究

发布时间：2018-11-04 12:15

【摘要】：聚丙烯是一种性能优良的热塑性树脂,具有价格低廉和加工性能好等特点,广泛应用于国民生产的各个领域,全球聚丙烯需求量在过去10年的平均增长率约为4.5%。聚丙烯树脂的广泛应用得益于Ziegler-Natta催化剂的不断更新换代,在催化剂体系中引入各类新型内给电子体,不仅提高了催化剂活性,而且改善了催化剂的定向能力和氢调敏感性。针对目前国内高端共聚聚丙烯催化剂大量依赖进口以及中石油尚未拥有自主知识产权的共聚聚丙烯催化剂的现状,根据已有内给电子体的基本结构,本文设计、合成了8种新型内给电子体,根据其性质特点,按照不同的制备方法将8种内给电子体负载在氯化镁晶体表面,制备成负载型Ziegler-Natta聚丙烯催化剂并进行相应的物性表征,发现催化剂Cat6和Cat8的各组分含量指标与工业用催化剂CSII相当。将自制的8种负载型催化剂进行丙烯聚合评价实验,比较含有不同内给电子体的负载型催化剂之间性能的差异,并以Cat6和Cat8为例,考察Si/Ti、氢气和内给电子体含量对催化剂性能的影响。实验结果表明,随着Si/Ti不断增大,催化剂活性下降,聚合物的等规度和熔点升高；随着氢气量不断增加,催化剂活性和聚合物熔融指数都在增加；随着催化剂体系中内给电子体含量不断降低,催化剂活性和聚合物等规度先是不断增加而后降低,当Mg/ED=10时达到峰值。
[Abstract]:Polypropylene (PP) is a kind of thermoplastic resin with excellent properties, such as low price and good processability. It is widely used in various fields produced by Yu Guomin. The average growth rate of global polypropylene demand in the past 10 years is about 4.5%. The extensive application of polypropylene resin is due to the continuous upgrading of Ziegler-Natta catalysts and the introduction of various new internal electron donors into the catalyst system, which not only improves the catalytic activity, but also improves the orientation ability and hydrogen sensitivity of the catalysts. In view of the current situation of domestic high-end polypropylene copolymers which rely heavily on imports and PetroChina does not have independent intellectual property rights, according to the basic structure of the existing internal donor electron body, this paper designs, Eight new types of internal electron donor were synthesized. According to their properties and characteristics, eight kinds of internal donor were loaded on the surface of magnesium chloride crystal according to different preparation methods. The supported Ziegler-Natta polypropylene catalyst was prepared and its physical properties were characterized. It was found that the contents of Cat6 and Cat8 in the catalyst were equal to those in the industrial catalyst CSII. Eight kinds of self-made supported catalysts were evaluated for propylene polymerization. The differences of performance among the supported catalysts containing different internal electron donors were compared. Cat6 and Cat8 were taken as examples to investigate Si/Ti,. Effects of hydrogen and the content of internal electron donor on the performance of the catalyst. The experimental results show that with the increasing of Si/Ti, the activity of the catalyst decreases, the isotacticity and melting point of the polymer increase, and the activity of the catalyst and the melting index of the polymer increase with the increase of hydrogen content. With the decrease of the content of electron donor in the catalyst system, the activity of the catalyst and the isotacticity of the polymer increased at first and then decreased, and reached the peak at 10:00 of Mg/ED=.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TQ325.14

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