http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Iku Kouzai (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Role of Dispersion State of Ti Species in Deactivation of MgCl2-Supported Ziegler-Natta Catalysts
Toshiaki Taniike,Toru Wada,Iku Kouzai,Shougo Takahashi,Minoru Terano 한국고분자학회 2010 Macromolecular Research Vol.18 No.9
The deactivation behaviors of TiCl3/MgCl2 model catalysts with molecularly dispersed TiCl3 were investigated to clarify the role of the dispersion state of the Ti species in the deactivation of MgCl2-supported Ziegler-Natta (ZN) catalysts for propylene and ethylene polymerization. The propylene and ethylene polymerization activities of clustered Ti species supported on MgCl2 were approximately one tenth of those of isolated Ti species, which is indicative of the significance of the aggregation of Ti species in the deactivation of ZN catalysts for olefin polymerization. Moreover, the time-course depression of monomer consumption for the clustered Ti species was slower than that for the isolated Ti species in propylene polymerization, whereas the dispersion state barely affected the depression rate in ethylene polymerization. The reduction rate of the Ti species was concluded to be important for the time-course depression of propylene consumption, whereas ethylene polymerization was insensitive to the oxidation state of the Ti species.
-
Toshiaki Taniike,Shougo Takahashi,Toru Wada,Iku Kouzai,Minoru Terano 한국고분자학회 2010 Macromolecular Research Vol.18 No.9
The dispersion state of surface Ti species is one of the most important factors affecting the polymerization properties of MgCl2-supported heterogeneous Ziegler-Natta catalysts. In this paper, ethylene-propylene copolymerization was carried out using a novel Ziegler-Natta model catalyst with “isolated” and “clustered” TiCl3 molecules on MgCl2. At a lower ethylene/propylene feed ratio, the dispersion state of the Ti species strongly affected both the composition and sequence distribution of the copolymers. The “isolated” Ti species gave a relatively random copolymer, and clustering of Ti species enhanced the bulkiness. The addition of an external donor basically deteriorated the random copolymerization character of the “isolated Ti species but the degree of deterioration depended on the type of donors. On the other hand, the balance between the monomer feed and consumption dominated the copolymerization performance at a higher ethylene/propylene feed ratio to obscure the effects of the dispersion state.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
