Precise control of microstructure of functionalized polypropylene synthesized by the ansa-zirconocene/MAO catalysts

We inclusively investigated polymerization behavior and structure of copolymer in the copolymerization of propylene and alkylaluminum-protected polar allyl monomers. The control of the arrangement of polar group in the copolymer was discussed. It was proved that the location of polar group could be controlled by zirconocene catalyst and a kind of polar monomer. The indenyl or the 2-methylindenyl ligands of zirconocene were favored to produce end-functionalized polymers. It was also found that the trimethylaluminum-protected allylamine and triisobutylaluminum-protected allyllmercaptan had superior ability in the synthesis of end-functionalized polypropylene. On the other hand, the 2-methyl-4-phenylindenyl ligand produced the copolymers containing both the end-polar unit and inner-polar unit at the polymer chains. Terpolymerization of propylene, polar allyl monomer, and 5-hexen-1-ol was also conducted. The NMR study of the terpolymer revealed that both the 5hexen-1-ol and the polar allyl monomer were incorporated into the polymer chain. It has also become apparent that the polar allyl monomer units predominantly occupied the chain end, while the 5-hexen-1-ol units were located at the inner of main chain. Consequently, we have achieved the synthesis of functionalized polypropylene in which the arrangement of polar group was precisely controlled. (c) 2008 Wiley Periodicals, Inc.