Surface Properties of Butanol Phosphate Esters in Alkali Solutions

Phosphate esters of two butanol isomers were synthesized by esterification of n-butanol and isobutanol with phosphorus pentoxide. The surface activity and penetrability of the esters were analyzed by way of surface chemistry and canvas disc wetting tests in different alkaline solutions. The surface tension of the butanol phosphate esters and their sodium salts was found to decrease with increasing alkaline concentration up to 250 g/L NaOH. Furthermore, the products exhibited a good surface activity with proper penetrability even in highly alkaline solutions. The stable surface activity of the esters in concentrated alkali lye interpreted by the adsorption of the molecule from solution owing to the common ion effect.