| 초록 |
Co metal related catalysts for butadiene homopolymerization have been attained great attention due to their ability to tune the microstructure of resulting polymer chain. A series of Co saloph type precatalysts were synthesized. Studies about the factors influencing cis polymerization, in particular, effect of reaction parameters such as temperature, structural difference made in ligand by the change in substituents, Al/Co molar ratio, etc. were studied. The catalysts evidenced very high activity yielding polybutadiene (PBD) chains with narrow molecular weight distribution and moderately high number average molecular weights. PBD chains produced were found to have polymer chains resulted from 1,2- and 1,4- additions. Polymers from 1,4-addition was the major fraction with very high cis- content. A detailed investigation in which metal center geometry through out the polymerization process and hence the active species identification was carried out through UV-Vis spectroscopy. |
