Heterogeneous Supported Catalysts for Butadiene Polymerization: The Effect of Calcination Temperature and Solvent

The polymerization of butadiene was studied using heterogeneous cobalt nickel (oxide) bimetallic catalyst. The prepared catalyst was subjected to calcination at different temperatures. This treatment results in the formation of different phases with multiple oxidation states. The characterization of the catalyst was carried out by XRD, SEM, EDX, TGA, FTIR and TPR/TPD. The catalytic activity was studied for the polymerization of butadiene gas in toluene, n-hexane and ethanol in a Parr reactor system. The products obtained, were characterized by FTIR, GC/MS, 1 H and 13 C NMR spectroscopy, Laser Light Scattering (LLS) and GPC. The best activity was achieved on the catalyst sample calcined at 1173 K in ethanol solvent. The product contains aliphatic and aromatic carbonyl compounds and polybutadiene terminated by OH group. The GPC and LLS studies indicates that polydispersity of the products are in the narrow range and high molecular weight product. The study reflects that the catalytic reaction conditions, the calcinations temperatures which control the oxidation state, phase of the catalyst and stability of the catalyst are mainly responsible for the change in products selectivity.