Preparation of high vinyl polybutadiene rubber via coordination polymerization with low-steric-hindrance alkoxy multi-substituted molybdenum

A series of molybdenum based catalyst systems substituted with low alkoxy blocking ligands for the polymerization of 1,3-butadiene were synthesized, and polybutadiene with high vinyl content was prepared. The results showed that the low alkoxy ligand could balance the relationships between ligand steric hindrance and catalyst solubility. The mass fraction of polybutadiene bound vinyl was more than 86%, and the catalytic activity of ethoxy bridged catalyst could reach 1.520×105 g/(mol·h), which was the molybdenum based catalytic system for high vinyl polybutadiene with the highest polymerization catalytic activity reported so far.