Additive Effect of Triphenylphosphine on the Living Polymerization of 1,3‐Butadiene with a Cobalt Dichloride‐Methylaluminoxane Catalytic System

摘要: The additive effect of triphenylphosphine (Ph3P) was investigated in 1,3-butadiene polymerization with cobalt dichloride (CoCl2) activated by methylaluminoxane (MAO); the catalytic system resulted slowly-initiated living a high cis-1,4 content (about 99%) at 0 °C. behavior, such as relationship polymer yield and number-average molecular weight () time, dependent on amount Ph3P added. In presence small (Ph3P/Co = 0.025), kinetic behavior qualitatively resembled that observed absence Ph3P, which indicated conducted polymerization. An increase (Ph3P/Co > 0.025), however, caused chain transfer reaction. 1H NMR analysis produced polymers showed changed microtacticity from 99% to 88% 1,2-unit, depending At maximum (Ph3P/Co = 0.025) necessary for maintaining livingness propagating species, 14% 1,2-inserted unit incorporated expense cis-1,4-inserted unit. addition during did not affect gave regio-block copolymer 1,3-butadiene. Number-average function time.