Abstract:The polymerization of butadiene (Bd) was initiated by coordination catalysis system,which consists of molybdenum chloride (MoCl5) as main catalyst, tributyl phosphate as ligand (TBP) and triethyl aluminum (AlEt3) as cocatalyst. The effect of catalytic system ratio and polymerization temperature on the polymerization activity of butadiene was studied . The results show that with increase of the Mo/Bd mole ratio and the Al/Mo mole ratio, the polymerization activity increases significantly, the intrinsic viscosity and molecular weight of the polymer show the trend of first increasing and then decreasing, the molecular weight distribution slightly becomes narrow; with the polymerization temperature increased, the polymerization speed increases, the intrinsic viscosity of the polymer first increases and then decreases. The polymerization of butadiene initiated by MoCl5/TBP/AlEt3 catalytic system can prepare the random 1,2-polybutadiene of which the 1,2-structure content is more than 75%, and the stereoregularity of the polymer is less affected by change of the polymerization temperature. With increase of the Al/Mo mole ratio, the orientation increases, the content of 1,2-structure of polymer increases between the range of 78%~84%, and a small amount of microcrystalline structure appears in the polymer. The existence of the crystal structure is of great significance to improvement of the mechanical properties of rubber materials.