| 摘要 |
A method for preparing high cis-1,4 polybutadiene by a continuous process which involves the continuous polymerization of 1,3-butadiene in solution under adiabatic conditions is provided. The method comprises the steps of: (I) feeding continuously to a single agitated polymerization reactor: (a) a monomer stream comprising 1,3-butadiene in a hydrocarbon solvent; (b) a preformed pi allyl catalyst stream formed by admixing a carboxylated metal oxy borate compound represented by the formulae (RCOOMO)3B or (ROCOOMO)2B-OR' wherein R and R' are alkyl radicals containing from 7 to 17 carbon atoms and M is nickel or cobalt, an organo aluminum compound, an alcohol, a small amount of 1,3-butadiene and a hydrocarbon solvent; and (c) a cocatalyst stream comprising a boron trifluoride complex with an alcohol; and (II) withdrawing continuously from said reactor high cis-1,4 polybutadiene at the same rate as said monomer, preformed catalyst and cocatalyst streams are fed to the reactor. In an additional embodiment of the invention, a method of preparing a preformed pi allyl catalyst having improved stability and solubility in hydrocarbon solvent is provided. High cis-1,4 polybutadiene polymers produced by the method of the invention have good green strength and tack and may be used as tire rubbers and impact modifiers for plastics. |
