| 학회 | 한국고분자학회 |
| 학술대회 | 2004년 가을 (10/08 ~ 10/09, 경북대학교) |
| 권호 | 29권 2호, p.141 |
| 발표분야 | 고분자 합성 |
| 제목 | The Effect of Solvent Polarity on the Initiation and the Propagation of Ethylene Polymerization with Constrained Geometry Catalyst/MAO Catalytic System: A Density Functional Study with the Conductor-like Screening Model |
| 초록 | The effects of solvent polarity on the initiation and the propagation of ethylene polymerization with constrained geometry catalyst (CGC) and MAO counterion (Figure 1) were investigated by the density functional theory (DFT) with the conductor-like screening model1,2 (COSMO). Structures and energetics during insertion of ethylene monomers into the catalytic active species of ionic pair and/or cationic catalyst were analyzed for gas state and solvent states. The comparative analysis on the energetics of the ethylene insertion in gas state and in solvent states each with different dielectric constants (ε) shows that the insertion mechanism in conjunction with conterion is altered by the solvent polarity, which is closely related to the degree of exposure of Ti atom on the solvent medium and the degree of separation of ionic pair during monomer insertion. This result suggests that the mechanism of monomer insertion as well as the active catalytic species is altered by the solvent polarity not only quantitatively but also qualitatively. Figure 1. Structure of ionic pair of CGC and MAO counterion. References 1. A. Klamt and G. Schüürmann, J. Chem. Soc. Perkin trans. 2 799 (1993). 2. A. Klamt, V. Jonas, T. Bürger, and J. C. W. Lohrenz, J. Phys. Chem. A 102, 5074 (1998). |
| 저자 | 양성훈, 허준, 조원호 |
| 소속 | 서울대 |
| 키워드 | Density Functional Theory; Constrained Geometry Catalyst; Ethylene polymerization; Solvent Polarity |
