| 학회 | 한국고분자학회 |
| 학술대회 | 2005년 봄 (04/14 ~ 04/15, 전경련회관) |
| 권호 | 30권 1호, p.137 |
| 발표분야 | 고분자 합성 |
| 제목 | Polymerization of 1,3-Butadiene with Cobalt(II) Pyridyl Bis(imine) Complexes : Effect of Ligand Bulkiness |
| 초록 | In 1954, it was discovered that the catalyst system TiCl4-AlR3 polymerizes isoprene into cis-1,4-polymer. Later it has been found that catalyst systems composed of a Ti, Co, Ni, V, or rare earth metal compound and an organoaluminum give cis-1,4-polybutadiene. There has been recent interest in the use of soluble transition metal catalysts such as titanocene/methyl alumoxane (MAO) catalysts, Ti(OiPr)4/MAO, Ti(CH2Ph)4/MAO, Ni(acac)2/MAO, and Ni(oct)2/AlF3/AlEt3 for 1,4-polymerizations of isoprene and 1,3-butadiene to obtain high molecular weight polymers with low polydispersities as efficient low-cost materials for improved synthetic rubber. Catalysts consisting of a cobalt compound and an alkylaluminum chloride readily dissolve in hydrocarbon solvents such as C4-C8 n-alkanes, benzene or toluene and are effective for the cis-1,4-polymerization of butadiene. A variety of Co compounds are available, such as CoL2 (L = F, Cl, Br, I ) complexed with some bases (pyridine, alcohols, etc.) and cobalt salts of organic acids. However, the use of cobalt complexes bearing well designed ligands have not been reported yet. More recently, Yasuda et al. reported iron-terpyridine complexes, [Fe(terpyridine)2](FeCl4)2, FeCl3(terpyridine), and FeCl3(4,4’,4”-tri-tert-butylterpyridine), were found to display high catalytic activities for 1,2/3,4-polymerizations of isoprene and trans-1,4-polymerization of 1,3-butadiene in the presence of modified methylalumoxane. Recently Brookhart et al. reported new cationic tridentate Fe(II)- and Co(II)-based pyridylbis(imine) catalysts were very effective for the polymerization of olefins in the presence of MAO cocatalyst. The large number of possible variations in these catalyst systems allow for more specifically designed catalysts, possibly selective for the optimized polymerizations of desired conjugated dienes. As a result, we decided to find the efficient catalysis using Co(II)-based pyridyl bis(imine) complexes for polymerizations of 1,3-butadiene. In this communication we report our preliminary results obtained in the polymerization of 1,3-butadiene promoted by a series of prototypical Co(II)-based pyridylbis(imine) complexes (Fig. 1) in the presence of alkylaluminum cocatalyst. |
| 저자 | 김재성, 하창식, 김일 |
| 소속 | 부산대 |
| 키워드 | polybutadiene; late transtion metal catalyst; 1; 3-butadiene; cis-1; 4-polymerization |
