Synthesis and characterization of high cis-polybutadiene:: influence of monomer concentration and reaction temperature

This paper reports the study of the dependence of reaction conversion, catalyst activity, polymer microstructure, molecular weight, molecular weight distribution curves and Mooney viscosity on reaction temperature and monomer concentration in the reaction medium used in the synthesis of high cis-polybutadiene. A ternary catalyst system composed by neodymium versatate, trans-butyl chloride and diisobutylaluminum hydride was used in its synthesis. The highest molecular weights were obtained at polymerization temperatures in the range from 70 to 80 degreesC. The highest content of cis-1,4 repeating units (about 99%) was observed when the polymerization was carried out at the lowest initial monomer concentration (0.56 mol/l). (C) 2004 Published by Elsevier Ltd.