Ethoxylates

The reaction between ethylene oxide and long-chain fatty alcohols or fatty acids is called ethoxylation. Ethoxylation of C₁₀-C₁₄ linear alcohols and linear alkylphenols produces nonionic detergents. The reaction with alcohols could be represented as:

The solubility of the product ethoxylates can be varied according to the number of ethylene oxide units in the molecule. The solubility is also a function of the chain-length of the alkyl group in the alcohol or in the phenol. Longer-chain alkyl groups reduce water solubility. In practice, the number of ethylene oxide units and the chain-length of the alkyl group are varied to either produce water-soluble or oil-soluble surface active agents. Surfactants properties and micelle formation in polar and nonpolar solvents have been reviewed by Rosen. Linear alcohols used for the production of ethoxylates are produced by the oligomerization of ethylene using Ziegler catalysts or by the Oxo reaction using alpha olefins. Similarly, esters of fatty acids and polyethylene glycols are produced by the reaction of long-chain fatty acids and ethylene oxide:

The C_l2-C_l8 fatty acids such as oleic, palmitic, and stearic are usually ethoxylated with EO for the production of nonionic detergents and emulsifiers.