Polar Isotactic And Syndiotactic Polypropylenes By Organozirconium-Catalyzed Masking-Reagent-Free Propylene And Amino-Olefin Copolymerization

Polar functionalized isotactic and syndiotactic polypropylenes (PPs) are synthesized by direct, masking-reagent-free propylene and amino-olefin (AO, CH2=CH(CH2)(x)(NPr2)-Pr-n,x=2, 3, 6) copolymerizations using the activated precatalystsrac-[Me2Si(indenyl)(2)]ZrMe(2)and [Me2C(Cp)(fluorenyl)]ZrMe2, respectively. Polymerization activities at 25 degrees C are as high as 4208 and 535 kg/(mol h atm) with AO incorporation up to 4.0 mol % and 1.6 mol %, respectively. Remarkably, introducing the amino-olefin comonomers significantly enhances stereoselection for both isotactic (mmmm: 59.5 %-> 91.0 %) and syndiotactic (rrrr: 66.3 %-> 81.3 %) products.