Formula C6H15BO3 Appearance clear liquid Molar mass 145.99 g·mol−1 Boiling point 118 °C (244 °F; 391 K) | Density 858 kg/m³ Pubchem 9009 Melting point −85 °C (−121 °F; 188 K) | |
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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 the reaction of boric acid and ethanol in the presence of acid catalyst, where it forms according to the equilibrium reaction:
B(OH)3 + 3 C2H5OH ⇌ (C2H5O)3B + 3 H2OIn order to increase the rate of forward reaction, the formed water must be removed from reaction media by either azeotropic distillation or adsorption. 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.