Copolymerization Of Ethylene With Acrylonitrile Promoted By Novel Nonmetallocene Catalysts With Phenoxy-Imine Ligands

A series of novel nonmetallocene catalysts with phenoxy-imine ligands was synthesized by the treatment of phthaldialdehyde, substituted phenol with TiCl4, ZrCl4, and YCl3 in THF. The structures and properties of the catalysts were characterized by 1H NMR and elemental analysis. These catalysts were used for copolymerization of ethylene with acrylonitrile after activated by methylaluminoxane (MAO). The effects of copolymerization temperature, Al/M (M = Ti, Zr, and Y) ratio in mole, concentrations of catalyst and comonomer on the polymerization behaviors were investigated in detail. These results revealed that these catalysts were favorable for copolymerization of ethylene with acrylonitrile. Cat.3 was the most favorable one for the copolymerization of ethylene with acrylonitrile, and the catalytic activity was up to 2.19 X 104 g PE/mol.Ti.h under the conditions: polymerization temperature of 50 degrees C, Al/Ti molar ratio of 300, catalyst concentration of 1.0 X 104 mol/L, and toluene as solvent. The resultant polymer was characterized by FTIR, cross-polarization magic angle spinning, 13C NMR, WAXD, GPC, and DSC. The results confirmed that the obtained copolymer featured high-weightaverage molecular weight, narrow molecular weight distribution about 1.611.95, and high-acrylonitrile incorporation up to 2.29 mol %. Melting temperature of the copolymer depended on the content of acrylonitrile incorporation within the copolymer chain. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012