Tributyl phosphate (TBP), also known as phosphoric acid tri-n-butyl ester and tri-n-butyl phosphate, has the molecular formula (CH3CH2CH2CH2O)3PO, molecular weight 266.31. Its CAS number is 126-73-8. It is a common industrial chemical used in plasticizers and paints. Tributyl phosphate is a very strong, aprotic and polar solvent.
The chemical has both commercial and military applications, including as a plasticizer for cellulose esters, lacquers, chlorinated rubber, PVC, plastic and vinyl resins; heat exchange medium; solvent for nitrocellulose and cellulose acetate; pigment grinding assistant; painting additive; printing ink solvent; antifoam agent; dielectric; adhesive; and may be used for the production of synthetic resin and natural rubber solutions. . It is used as a defoamer in concrete additives (especially in concrete containing lignin sulfonate as a fluidizer); textile processing chemicals (especially in combination with wetting agents); and glues and adhesives, paper coating slurries, plastic dispersions, drilling fluids, cementations, lubricants, coatings, electroplating. TBP is used as an extracting agent in liquid-liquid extraction, e.g. for the separation and recovery of rare earths and platinum metals, in the cleaning of phosphoric acid, sulfuric acid, nitric acid, and hydrofluoric acid, and