Synthesis of Hydroxyl Group Containing Polyolefins with Metallocene/Methylaluminoxane Catalysts

Abstract

Ethylene and propylene were copolymerized with 10-undecen-1-ol, using stereorigid Et[Ind]2ZrCl2, Me2Si[Ind]2ZrCl2, Me2Si[2-MeInd]2ZrCl2, and Me2Si[2-Me-4,5-BenzoInd]2ZrCl2 catalysts activated with methylaluminoxane (MAO). As a reference, ethylene copolymerization was also carried out with the nonstereospecific catalyst [Ind]2ZrCl2/MAO. Characterization of the copolymers by 13C and 1H NMR spectroscopy revealed that the polymerization product was a true copolymer and that the conversion of the polar comonomer was strongly favored by the chiral geometry of the catalyst. The pretreatment of 10-undecen-1-ol with MAO before initiating the copolymerization increased the ethylene polymerization rate markedly and slightly improved the reactivity of the polar comonomer. A major improvement in the polymerization rate of 10-undecen-1-ol was obtained when the polymerization temperature and Al/Zr mole ratio were increased.