| 학회 | 한국고분자학회 |
| 학술대회 | 2005년 가을 (10/13 ~ 10/14, 제주 ICC) |
| 권호 | 30권 2호 |
| 발표분야 | 고분자 합성 |
| 제목 | Highly cis-selectivity Polymerization of 1, 3-Butadiene with Cobalt (II) Diazene Complexes |
| 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. Here, we have synthesized a series of neutral cobalt (II) complexes of bidentate ligand comprising a diazene function –N=N- as a donor. The ligands were prepared from aniline and 2-naphtol by azo coupling. Cobalt (II) complexes (Figure 1) were obtained by reaction of the ligand with 0.5 equiv of cobalt acetate in methyl alcohol. It was found that the cobalt (II) diazene complexes could be utilized for the 1,3-butadiene polymerization in the presence of ethylaluminum sesquischloride (EAS) as cocatalyst under ambient conditions. Figure 1. Series of the cobalt(Ⅱ) diazene complexes |
| 저자 | 김재성, 하창식, 김일 |
| 소속 | 부산대 |
| 키워드 | late transition metals; 1; 3-butadiene; polybutadiene; ligand structure variation; microstructure |
