|Amorphous boron is used in pyrotechnic
flares to provide a distinctive green color, and in rockets as an
igniter. By far the most commercially important boron compound in
terms of dollar sales is Na2B4O7.5H2O.
This pentahydrate is used in very large quantities in the manufacture of
insulation fiberglass and sodium perborate bleach.
Boric acid is also an important boron
compound with major markets in textile products. Use of borax as a mild
antiseptic is minor in terms of dollars and tons. Boron compounds are
also extensively used in the manufacture of borosilicate glasses. Other
boron compounds show promise in treating arthritis.
The isotope boron-10 is used as a control
for nuclear reactors, as a shield for nuclear radiation, and in
instruments used for detecting neutrons. Boron nitride has remarkable
properties and can be used to make a material as hard as diamond. The
nitride also behaves like an electrical insulator but conducts heat like
It also has lubricating properties
similar to graphite. The hydrides are easily oxidized with considerable
energy liberation, and have been studied for use as rocket fuels. Demand
is increasing for boron filaments, a high-strength, lightweight material
chiefly employed for advanced aerospace structures.
Boron is similar to carbon in that it has
a capacity to form stable covalently bonded molecular networks.
Carbonates, metalloboranes, phosphacarboranes, and other families
comprise thousands of compounds.