Triethyl borate, also called boron triethoxide or boric acid, triethyl ester, is a colorless, flammable liquid with the formula B(C2H5O)3. It is an ester of boric acid and ethanol.
It melts at −85 °C and boils at 118 °C. It is flammable, with flash point at 11 °C.
It burns with a green flame and solutions of it in ethanol are therefore used in special effects and pyrotechnics.
It is formed by dissolving boric acid in ethanol, where it forms according to the equilibrium reaction:
- B(OH)3 + 3 C2H5OH (C2H5O)3B + 3 H2O
It is used as a solvent and/or catalyst in preparation of synthetic waxes, resins, paints, and varnishes. It is used as a component of some flame retardants in textile industry and of some welding fluxes.