POLYMERIZATION OF EPOXIDES CATALYZED BY THE TITANIUM TETRAISOPROPOXIDE PHENOL SYSTEM AND ITS MECHANISM

Although the polymerization of epoxides catalyzed by titanium alkoxides has been reported, the mechanism is still unknown. The authors' examination of this process revealed that cyclohexene oxide gave a polymer in a very low yield in the presence of a catalytic amount of titanium tetraisopropoxide. This result is probably because the Lewis basicity of the epoxide is too weak to facilitate its coordination to the metal center of the weak Lewis acid titanium tetraisopropoxide. They now find that the addition of phenol to titanium tetraisopropoxide causes a remarkable effect on the polymerization of epoxides and that the phenoxy and isopropoxy groups play distinct roles for initiating the polymerization. 1 Ref.