ISOTACTIC OLEFIN POLYMERIZATION WITH OPTICALLY-ACTIVE CATALYSTS

With the homogeneous Ziegler-Natta catalyst based on chiral metallocenes/methylalumoxane highly isotactic polypropylene could be prepared. The catalysts can be separated into the optical active enantiomers. Even longer chained alpha-olefins as butene-1, pentene-1, or hexene-1, give isotactic polymers. Among the polymer features molecular weight and molecular weight distribution, solubility in toluene, melting point, density, and x-ray crystallinity as well as macrotacticity have been examined. Except for polyhexene all polymers investigated arrange in a stable helical conformation. Oligomers of butene-1 and pentene-1 show an optical rotation.