Journal of Applied Polymer Science, Vol.71, No.4, 595-602, 1999
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) were prepared by an alcohol interchange reaction between neodymium chloride n isopropanolate (I) with pentanols. These NdCl3 tripentanolates (II-IV) were characterized by gravimetric and elemental analysis. They were evaluated for homopolymerization of 1,3-butadiene using triethyl aluminum as cocatalyst in cyclohexane solvent. The role of positional isomers of pentanols (1, 2, and 3) in catalytic activity on conversion, intrinsic viscosity, and microstructure was studied. The neodymium chloride tripentanolate-2 (III) has high catalytic activity followed by (II) and (TV). The conversions were increased with increases in catalyst, cocatalyst concentrations, and temperature, and decreases in intrinsic viscosity values. The microstructure was determined 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.