We describe the synthesis of a styrene–ethylene copolymer using a trivalent titanium-based polymerization catalyst system, tris(acetylacetonate)titanium/triisobutylaluminum-modified methylaluminoxane (MMAO). The catalyst system yielded a mixture of two different polymers. 13C nuclear magnetic resonance analysis of Soxhlet-extracted fractions indicated that the Soxhlet-soluble part contains the syndiotactic styrene–styrene sequence and the ethylene units adjacent to continuous styrene units. Consideration about a relation among sequence distribution, styrene content and thermal property data reasonably indicates that the block-like copolymer was produced, which contains the long syndiotactic polystyrene portions separated by the ethylene units.
- Hideaki Hagihara
- Chiharu Usui
- Naofumi Naga
