Polymerization of 1,3-butadiene using neodymium chloride tripentanolate triethyl aluminum catalyst systems

Neodymium chloride tripentanolate catalysts of the general formula NdCl3 x nL with n = 3, L = I-pentanol(II), 2-pentanol (III), and 3-pentanol (IV) we re prepared by an alcohol interchange reaction between neodymium chloride n isopropanolate (I) with pentanols. These NdCl3 tripentanolates (II-IV) wer e characterized by gravimetric and elemental analysis. They were evaluated for homopolymerization of 1,3-butadiene using triethyl aluminum as cocataly st in cyclohexane solvent. The role of positional isomers of pentanols (1, 2, and 3) in catalytic activity on conversion, intrinsic viscosity, and mic rostructure was studied. The neodymium chloride tripentanolate-2 (III) has high catalytic activity followed by (II) and (TV). The conversions were inc reased with increases in catalyst, cocatalyst concentrations, and temperatu re, and decreases in intrinsic viscosity values. The microstructure was det ermined by Fourier transform-infrared spectroscopy (FTIR) and found to have a predominantly cis-1,4 structure (>99%), which was marginally influenced by variation in cocatalyst concentration and temperature. (C) 1999 John Wil ey & Sons, Inc.