Study of the molecular characteristics of the cationic polymerization products of ethylene oxide in the presence of polyfunctional alcohol

A study has been made of the molecular characteristics of oligomers of molecular weight from 130 to 400 obtained by polymerization of ethylene oxide in 1,2-dichloroethane in the presence of boron trifluoride etherate and glycerol. In this range of MW the oligomers contain no side products distorting the number average functionality, apart from an insignificant admixture of diols due to the presence of water in reagents. It was found by gas-liquid chromatography that the molecular weight distribution is of the Poisson type. The results of periodate oxidation and the presence of secondary OH groups point to formation of branched molecules (as in anionic polymerization processes) whose fraction increases in the course of polymerization.