Acid‐catalyzed additions of ethylene oxide to various isomeric butyl alcohols were observed to agree with the Poisson equation and the products were relatively unaffected in composition by changes in the reactants or reaction conditions. Base‐catalyzed reactions yielded products whose composition could be more closely approximated by Weibull and Nycander舗s equations. The product composition, although largely independent of reaction conditions, varied with the structure of the starting alcohol. Good correlation was found between the relative acidities of the starting alcohols and their reaction products and Weibull‐Nycander distribution constants for base‐catalyzed reactions of ethylene oxide and propylene oxide. It is believed that the relative acidities of the alcohol and its epoxide adduct influence the product composition through the equilibrium reaction: ROH+RO (CH2CH2O)=X薔RO蜢+RO(CH2CH2O)xH

The translation of the potentially hazardous, highly exothermic alkoxylation reaction to the rapid, safe and completely reliable industrial technology that it is today has been a noteworthy development. Commercially, the reactions of ethylene oxide with fatty acids are conducted in the presence of alkaline catalysts at temperatures above 100 C. The reaction proceeds in two steps. The first step is relatively slow and the product is predominantly ethylene glycol monoester. The second step occurs after approximately one mole ethylene oxide is reacted and all of the fatty acid is consumed. An increase in the ethylene oxide addition rate is observed, and polyethylene glycol esters are formed. Rapid transesterification also occurs, and the molar proportions of monoester, diester, and free polyol in the product approaches those predicted by the equilibrium assuming random esterification of the polyethylene glycol hydroxyl groups. The composition of polyoxyethylated fatty acids is similar to that obtained by the direct esterification of fatty acid with polyethylene glycol. The distribution of the ethylene oxide chain lengths in the polyethylene glycol portion of the product can be approximated assuming random addition of the epoxide.

The base‐catalyzed reaction of ethylene oxide with oleic acid can be divided into two stages. The first stage consists of a slow reaction of oleic acid with ethylene oxide to form principally ethylene glycol monooleate; other reactions such as esterification, transesterification and polyglycol formation lag behind. In the second stage, after the addition of approximately one mole of ethylene oxide, the reaction accelerates and transesterification equilibrium is rapidly attained. The composition of products containing several molecules or more of ethylene oxide can be calculated satisfactorily on the assumption of random addition of ethylene oxide and random esterification of the hydroxyl groups. The uncatalyzed reaction is much slower and transesterification equilibrium is attained slowly, if at all. A reaction mechanism based on the difference in basicities of the carboxylate and alkoxide ions (and the relative rates of the competitive ethylene oxide reactions) is presented for the base‐cat‐alyzed reaction.

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