"Synthesis of high cis-1,4-butadiene-isoprene rubber catalyzed by solubilized neodymium phosphate ester catalyst"

A homogeneous phosphate ester rare earth catalytic system was constructed with solubilized neodymium di(2-ethylhexyl) phosphate eater as the main catalyst, alkyl aluminum and aluminum chloride as co-catalyst and the third component, respectively. The copolymerization of butadiene and isoprene was catalyzed by this catalytic system. The effects of the composition and dosage of alkyl aluminum and aluminum chloride, catalyst dosage, and monomer feeding ratio on the properties of the copolymer were studied. The results showed that the catalytic system could efficiently catalyze the copolymerization of butadiene and isoprene, and the resulting polymer was a random butadiene-isoprene rubber with high cis-1,4-unit stereoregularity and narrow molecular weight distribution. When diisobutylaluminum hydride was chosen as the alkyl aluminum, the catalytic system exhibited reversible coordination chain transfer polymerization characteristics with 10.3 polymer molecular chains gene-rated per neodymium atom.