MoCl_4-(i-Bu)_2AlOAr体系引发丁二烯聚合的研究

STUDIES ON POLYMERIZATION OF BUTADIENE INITIATED BY MoCl_4-(i-Bu)_2AlOAr SYSTEM

由MoCl_4为主催化剂,(i-Bu)_3Al与酚类反应的产物(i-Bu)_2AlOAr为助催化剂所组成的催化体系,在加氢汽油中引发丁二烯聚合,研究酚类结构对聚合反应的影响。结果表明,带有推电子基团的酚类,可以提高丁二烯岵,聚合速度,其顺序为双酚A>间甲酚间>β-萘酚>苯酚>对氯酚。测定了丁二烯聚合的表现活化能E_α,催化剂利用率α,活性中心浓度[P~*],和活性中心的平均寿期(?)。

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 efficiencies a, the concentrations of active centers [p*] , and the average lifetime of active centers L have been determined at 40℃: Ea=71.2-94.2kJ/mole, a = 1.1-3.5% , [P*] = 0.8 -2.5×10-5 mole/l, L = 30-63min.