Boron oxide is a highly insoluble thermally stable boron source suitable for glass, optic and ceramic applications. oxide compounds are not conductive to electricity. however, certain perovskite structured oxides are electronically conductive finding application in the cathode of solid oxide fuel cells and oxygen generation systems. Search results for boron oxide at sigma-aldrich. compare products: select up to 4 products. *please select more than one item to compare Boron oxide, the pure form of b2o3, is a hard glassy material, granular in texture. exposed to the atmosphere it slowly absorbs water, reverting to boric acid. it is soluble in water but at a much slower rate than boric acid. Refractories. chemically bonded firebricks and castables require resistance to high temperature, abrasion, and corrosion. boric oxide is used as a binder for magnesia-based refractory bricks and as a stabilizer for dolomite refractory bricks, commonly used in steel-smelting furnaces.