Stereoregular polymerization of butadiene

initiated by catalyst system made up of Mocl2 and (i-Bu)2 AlOAr which are products of reaction of (i-Bu)sAl with various phenols

has been performed in hydroganated gasoline solvent. The effects of phenols structure on polymerization rate of butadiene have been studied. It was found that phenols having the electrondonating group can give a higher rate of butadiene polymerization than those having the electron-withdrow-ing group. The order of polymerization rate of butadiene goes as follows: bisphenol A>m-cresol>β-naphthol>phenol>p-chlorophenol. The overall activation energies Ea

the catalyst efficienceies a

the concentrations of active centers [p*]

and the average lifetime of active cen-ters L have been determined at 40℃:Ea=71.2-94.2kJ/mole

a=1.1-3.5%

[p*]=0.8-2.5×10-5mole/1

L=30-63min.