THE INFLUENCE OF THE CATALYST PREPARATION ON THE HOMOMERIZATION AND COPOLYMERIZATION OF BUTADIENE AND ISOPRENE

The catalyst system Nd(octanoate)3/Al2Et3Cl3/Al(iBu)3 (Et: ethyl, iBu: isobutyl) in heptane for the polymerization of butadiene and isoprene was examined. The concentration of Al2Et3Cl3, Al(iBu)3 and the order of addition of the components were varied. The results of the determin ation of conversion, microstructure, molar mass and molar mass distrib ution are illustrated. The optimum component concentration ratio (Nd(o ctanoate)3/Al2Et3Cl3/Al(iBu)3 = 1 : 1,5 : 25) at a catalyst concentrat ion of 1,0 mmol Nd/L was fixed and used for the copolymerization of bu tadiene and isoprene. Copolymers obtained under various monomer feed r atios were characterized by H-1, C-13 NMR spectroscopy, gel-permeation chromatography (GPC), and differential scanning calorimetry (DSC) inv estigations.