Preparation of boron nitride
Preparation of boron nitride from sodium tetraborate and amonium chloride
Ten grams of powdered sodium tetraborate 10 hydrate are heated in a nickel crucible with a Bunsen burner until dehydration is complete (30 min), as indicated by the cessation of escaping steam. The product is ground with 10 g of ammonium chloride in a mortar and this mixture is heated in a nickel crucible for one-half hour over the full name of a Meker burner. The product is cooled and pulverized and extracted three times with 1N hydrochloric acid. The residue is boiled with 100 ml of distilled water, filtered, and the white powder of boron nitride dried at 100°C. Yield 0.3-0.5 g.
Preparation of boron nitride from boric oxide and urea
Ten grams of finely powdered boric oxide are intimately ground with 20 g of urea and heated in a covered nickel crucible for about 30 minutes over a Meker burner with slowly rising temperature to a bright red heat. The cooled mass is treated as described above Yield 2.5g
Preparation of boron nitride from boric oxide and ammonia
Eighteen grams of well-ground boric acid are thoroughly mixed with 35 g of pure calcium phosphate Ca3(PO4)2 and gently heated in a crucible until no more water vapor escapes. When cold, the mass is reground and placed in a clay crucible fitted with a finely perforated asbestos cover, through the center of which a clay tube about 8 mm in diameter leads almost to the bottom of tile crucible. A moderate stream of dry ammonia gas (about 3 bubbles/sec) is led into the mixture, which is then heated under the hood for 45 minutes at bright red heat over a Meker burner. The fusion residue is treated with 100 ml of boiling water and stirred continuously while just enough concentrated hydrochloric acid is added from a separatory funnel to dissolve the calcium phosphate. The mixture should be barely acid at the end of the neutralization; about 60 ml of acid are required. The residual product is washed by decantation with 0.5N hydrochloric acid until free of calcium and phosphate ions, then filtered and dried at 100° C. Yield of boron nitride is 80-00%
The product is only slowly hydrolyzed by hot water but dissolves in concentrated mineral acids to an appreciable extent; hot aqueous sodium carbonate causes slow decomposition to sodium borate and ammonia.
Inorganic laboratory preparations, by G. G. Schlessinger, 17-18, 1962
boron nitride, elbor
Boron nitride, Elbor, Boron nitride (BN), Borazon, Elboron, Kubonit, Wurzin, azanylidyneborane, Geksanit R, Hexanite R, Boron mononitride, Hexanit R, Super mighty M, Kubonit KR, Elbor R, Denka GP, Elbor RM, Sho BN, Sho BN HPS, SP 1 (Nitride), UHP-Ex, Denka boron nitride GP, 10043-11-5, BN 40SHP, KBN-H10, Elbor LO 10B1-100, BZN 550, EINECS 233-136-6, 78666-05-4, nitriloborane, Bornitrid, boranylidyneamine, nitrure de bore, nitruro de boro, AC1L24WR, [BN], 255475_ALDRICH, Jsp000115, CHEBI:50883, MolPort-003-928-681, AKOS015833702, RTX-012265, LS-45155, FT-0623177, 3B4-2055, I14-17610, 165390-92-1, 54824-38-3, 56939-87-8, 58799-13-6, 60569-72-4, 69071-29-0, 69495-08-5
SP 1, CID66227