| 초록 |
The internal donors in Ziegler-Natta catalysts are essential components for not only catalytic performances but also properties of resulting polymers. However, owing to ambiguity of the molecular behavior of donors during catalyst preparation and polymerization, only limited number of donors has been commercialized and relationship between structures and performances of donors is still not clear. To solve this problem, donors having various structures were synthesized and evaluated. It was postulated that molecular weight distributions as well as catalytic performances were affected remarkably depending on both main structures and substituents of donors. Four atom spacers in succinates, maleates and ketoesters were more effective to broaden molecular weight distributions than three atom spacers in malonates. The existence of bulky substituents indicates broader molecular weight distributions. More evaluation results of catalysts using donors with different structures will be discussed. |
