ConclusionsA study of the sodium monoalkyl phosphates and sodium dialkyl phosphates has shown that the dialkyl esters, in general, possess markedly superior surfactant and detergent properties compared to the monoalkyl esters. This is true whether we are comparing equivalent mol wt mono‐ and diesters or when comparing those made from the same alcohols.The branched chain didecyl ester, in addition to giving aqueous solutions of exceptionally low surface tensions and possessing a very low critical micelle concentration, also performs exceptionally well in built detergents. In fact, our data indicate that its performance characteristics are considerably better than commercial surfactants used today in these types of products.