Ethoxylation of simple alcohols such as methanol, ethanol and butanol in the presence of tripropylamine, in addition to the main reaction products, results in by‐products from tripropylamine and ethylene oxide. This side‐reaction consumes tripropylamine, forming dipropylamine ethoxylates and alcohol ethoxylates. These compounds remain in the product and influence the commercial properties of alcohol oxyethylates.

The effect of an amine catalyst on oxyalkyalation of alcohols of low relative molecular mass was studied. The reactivity and selectivity of the formation of the ®rst homologues depend upon the alcohol, the alkylene oxide and the degree of oxyalkylation and decrease in the following order methanol b ethanol b butanol b 2-methylpropanol. The formation of the ®rst homologue is signi®cantly more selective in oxypropylation in comparison to oxyethylation. Triethylamine used as the catalyst undergoes by-reactions giving N,N-diethylethanolamine and then oxyethylated diethylamines which exhibit catalytic activity.

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Major products and by-products of the ethoxylation of diethylethanolamine and its solutions in methanol have been identified. Through gas chromatography and mass spectrometry, it has been found that by-products correspond to ethyldiethanolamine and its succeeding ethoxylates. In methanol ethoxylation, diethylethanolamine acts as a catalyst and also itself undergoes ethoxylation, forming two types of products.

The effect of catalyst (potassium hydroxide, triethylamine, and sulfuric acid) on oxyethylation and oxypropylation of methanol, ethanol, and butanol is studied. Exemplary optimization of the process is performed at selectivity equal to 90% of the monoglycol alkyl ether fraction. It is shown that the most advantageous for oxyalkylation of methanol are the alkaline catalysts, especially triethylamine. The same relationship was observed for oxypropylation of ethanol and butanol. However, in oxyethylation of ethanol and butanol much better results are obtained using sulfuric acid as the catalyst.