Preparation of Dinuclear Metallocene Complexes for High-Performance Supported Catalyst
- 주제(키워드) supported catalyst , metallocene catalyst , ethylene polymerization , silica , methylaluminoxane , slurry process
- 발행기관 아주대학교
- 지도교수 이분열
- 발행년도 2021
- 학위수여년월 2021. 2
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000030472
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
For application in commercial slurry and gas-phase processes, single-site homogeneous metallocene catalysts are typically immobilized on silica surfaces to control the size and morphology of the generated polymer particles. However, the main challenge limiting the commercialization of these catalysts is the enhancement of their productivity (measured in kg-PE/g-(supported catalyst)). Herein, we demonstrate that the productivity of supported catalysts can be enhanced by using dinuclear metallocene complexes instead of the conventional mononuclear analogs to prepare the supported catalysts. Thus, the productivity of the supported catalysts prepared by reacting methylaluminoxane (MAO)-treated silica (denoted as silica-MAO) with dinuclear ansa-metallocene complexes synthesized with silylene-bridged and thiophene-fused cyclopentadienyl ligands was almost twice that of the catalysts prepared with the mononuclear analogs. The enhanced productivity is because of the higher loading of the dinuclear complexes than that of the mononuclear analogs; the fed dinuclear complexes were entirely anchored on silica-MAO at 90-150 umol-Zr/g-(silica-MAO) feed, whereas only a part of the fed mononuclear metallocene complexes was anchored on silica-MAO even at 90 umol-Zr/g-(silica-MAO) feed. In addition, the supported catalysts prepared with the dinuclear complexes suppressed the formation of large polymer particles.
more목차
1. Introduction 1
2. Results and Discussion 2
2.1 Preparation of dinuclear ansa-metallocene complexes 2
2.2 Preparation of supported catalysts and ethylene polymerization 6
2.3 Characterization of polymers 11
3. Conclusions 14
4. Experimental Section 15
4.1 General remarks 15
4.2 Synthesis of ligands and complexes 15
4.3 Preparation of supported catalysts 20
4.4 Ethylene polymerization 20
5. Reference 21
6. Supporting information 29
