CIESC Journal ›› 2021, Vol. 72 ›› Issue (4): 2102-2112.DOI: 10.11949/0438-1157.20201036

• Catalysis, kinetics and reactors • Previous Articles     Next Articles

POSS-modified supported Ziegler-Natta catalyst and its ethylene /1-hexene copolymerization

WANG Ning1(),HUI Lei1,CHEN Mei1,3,LI Wei1(),ZHOU Qi2   

  1. 1.School of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, Zhejiang, China
    2.College of Materials and Chemical Engineering, Ningbo University of Technology, Ningbo 315016, Zhejiang, China
    3.College of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China
  • Received:2020-07-28 Revised:2020-11-17 Online:2021-04-05 Published:2021-04-05
  • Contact: LI Wei

POSS改性负载型Ziegler-Natta催化剂及其乙烯/1-己烯共聚反应

王宁1(),惠磊1,陈美1,3,历伟1(),周琦2   

  1. 1.宁波大学材料科学与化学工程学院,浙江 宁波 315211
    2.宁波工程学院材料与化学工程学院,浙江 宁波 315016
    3.浙江大学化学工程与生物工程学院,浙江 杭州 310027
  • 通讯作者: 历伟
  • 作者简介:王宁(1995—),女,硕士研究生,2411882089@qq.com
  • 基金资助:
    国家自然科学基金面上项目(21776141)

Abstract:

Macroporous SiO2 (Macro-SiO2) with an open framework structure and MgCl2 are used to form a composite carrier, and polysilsesquioxane (POSS) is introduced to form a spatially separated POSS/ MgCl2 nano-aggregate, which is prepared after loading TiCl4 modified Ziegler-Natta catalyst. The catalytic structure of POSS-free and modified catalysts was investigated by FTIR, TG, CO low-temperature IR spectroscopy, SEM and particle size analysis. The incorporated POSS contributed the formation of defect Mg4c2+ sites and Lewis acidic sites, where the more defect Mg sites facilitated the effective loading of TiCl4. The POSS-modified Ziegler-Natta catalyst exhibited exceptional activity reaching 1.03×106 g?(mol·h)-1 in ethylene/1-hexene copolymerization. Simultaneously, the ethylene-hexene copolymer with much higher comonomer contents (3.79%) and narrowed molecular weight distribution (MWD=3—6) was synthesized in the POSS modified catalyst.

Key words: Ziegler-Natta catalyst, Macro-SiO2, POSS, ethylene, 1-hexene, copolymerization

摘要:

采用具有开放型骨架结构的大孔SiO2(Macro-SiO2)与MgCl2形成复合载体,同时引入聚倍半硅氧烷(POSS)形成具有空间分隔作用的POSS/MgCl2纳米团聚体,负载TiCl4后制备得到改性Ziegler-Natta催化剂。采用红外分析、热重分析、CO低温吸附红外、扫描电镜、粒径分析等手段对POSS改性前后催化剂的结构进行表征,发现POSS的引入能诱导MgCl2形成更多Mg4c2+缺陷位点,并促进了Lewis酸性位点的形成,有利于TiCl4有效活性中心的负载。乙烯/1-己烯共聚结果表明,POSS改性催化剂活性较高,最高可达1.03×106 g?(mol?h)-1,同时具有更高的共聚能力,共聚产物中共聚单体摩尔分数可达3.79%,且聚合产物具有较窄的分子量分布(MWD=3~6)。

关键词: Ziegler-Natta催化剂, 大孔SiO2, 聚倍半硅氧烷, 乙烯, 1-己烯, 共聚

CLC Number: