DETERMINATION OF RELATIVE ETHOXYLATION RATE CONSTANTS FROM SUPERCRITICAL FLUID CHROMATOGRAPHIC ANALYSIS OF ETHOXYLATED ALCOHOLS

Based on ethylene oxide distributions in ethoxylated alcohols determined by supercritical fluid chromatography, a flexible computer model has been developed and applied to calculate relative ethoxylation rate constants for base-catalyzed ethoxylations of normal octanol. These distribution coefficients are not substantially affected by the presence of another alcohol and were found to increase with increasing ethylene oxide content of the reactant ethoxylates. Their values, however, change as the average ethylene oxide content of the ethoxylated alcohol reaction medium increases. Using distribution coefficients averaged over an ethylene oxide/alcohol molar ratio range of 2 to 10, model predictions closely match experimentally determined ethylene oxide oligomer distributions. © 1990 AOCS Press.