METALLOCENES FOR POLYPROPYLENE - POLYMERIZATION PERFORMANCE AND COMPUTER MODELING

The structures of eleven different metallocenes substituted with eithe r methyl and/or t-butyl groups were minimized by computer molecular mo deling. Using Comparative Molecular Field Analysis (CoMFA), a computer model was generated from the minimized metallocene structures and act ual polymerization performance. When the model was tested, a statistic ally valid correlation of the model's predicted DSC melting point with the observed DSC melting point was found. The model indicates the ext ent of the steric effect of these alkyl substituents and their influen ce on the DSC melting point.