Tributyl phosphate
Tributyl phosphate, known commonly as TBP, is an organophosphorus compound with the chemical formula 3PO. This colourless, odorless liquid finds some applications as an extractant and a plasticizer. It is an ester of phosphoric acid with n-butanol.
Production
Tributyl phosphate is manufactured by reaction of phosphoryl chloride with n-butanol.Production is estimated at 3,000–5,000 tonnes worldwide.
Use
TBP is a solvent and plasticizer for cellulose esters such as nitrocellulose and cellulose acetate, similarly to tricresyl phosphate. It is also used as a flame retardant for cellulose fabrics such as cotton. It forms stable hydrophobic complexes with some metals; these complexes are soluble in organic solvents as well as supercritical CO2. The major uses of TBP in industry are as a component of aircraft hydraulic fluid, brake fluid, and as a solvent for extraction and purification of rare-earth metals from their ores.TBP finds its use as a solvent in inks, synthetic resins, gums, adhesives, and herbicide and fungicide concentrates.
As it has no odour, it is used as an anti-foaming agent in detergent solutions, and in various emulsions, paints, and adhesives. It is also found as a de-foamer in ethylene glycol-borax antifreeze solutions. In oil-based lubricants addition of TBP increases the oil film strength. It is used also in mercerizing liquids, where it improves their wetting properties. It can be used as a heat-exchange medium. TBP is used in some consumer products such as herbicides and water-thinned paints and tinting bases.