Chemical Property of Boron
Chemical Property:
- Appearance/Colour:charcoal-grey pieces or black powder
- Melting Point:2180 °C
- Boiling Point:3650 °C
- PSA：0.00000
- Density:2.34 g/mL at 25oC(lit.)
- LogP:-1.18390
- Storage Temp.:Storage temperature: no restrictions.
- Solubility.:H2O: soluble
- Water Solubility.:insoluble H2O [MER06]
- Hydrogen Bond Donor Count:0
- Hydrogen Bond Acceptor Count:0
- Rotatable Bond Count:0
- Exact Mass:11.0093052
- Heavy Atom Count:1
- Complexity:0
- Purity/Quality:
-
99% *data from raw suppliers
B- *data from reagent suppliers
Safty Information:
- Pictogram(s):
Xn; 
F
- Hazard Codes:Xn,F
- Statements:
22-11-63-62
- Safety Statements:
16-24/25-45-36/37/39-27-26
- MSDS Files:
-
SDS file from LookChem
Total 1 MSDS from other Authors
Useful:
- Chemical Classes:Metals -> Elements, Metallic
- Canonical SMILES:[B]
- Recent ClinicalTrials:Measuring Acute Drug Demand in Humans
- Recent EU Clinical Trials:Signal TrAnsduction Pathway activity analysis for OVarian cancER treatment. STAPOVER study
- Recent NIPH Clinical Trials:Boron neutron capture therapy using cyclotron-based epithermal neutron source for squamous cell carcinoma of the head and neck refractory to standard treatments: An open-label phase II trial
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Description
Boron was discovered by Sir Humphry Davy and J.L. Gay-Lussac in 1808. It is a trivalent non-metallic element that occurs abundantly in the evaporite ores borax and ulexite. Boron is never found as a free element on Earth. Boron appears as charcoal-grey pieces or black powder or as crystalline; is a very hard, black material with a high melting point; and exists in many polymorphs.
Boron has several forms, and the most common one is amorphous boron, a dark powder, non-reactive to oxygen, water, acids, and alkalis. It reacts with metals to form borides. Boron is an essential plant micronutrient. Sodium borate is used in biochemical and chemical laboratories to make buffers. Boric acid is produced mainly from borate minerals by the reaction with sulphuric acid. Boric acid is an important compound used in textile products. The most economically important compound of boron is sodium tetraborate decahydrate or borax, used for insulating fibreglass and sodium perborate bleach. Compounds of boron are used in organic synthesis, in the manufacture of a particular type of glasses, and as wood preservatives. Boron filaments are used for advanced aerospace structures, due to their high strength and light weight.
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Physical properties
Boron has only three electrons in its outer shell, which makes it more metal than nonmetal.Nonmetals have four or more electrons in their valence shell. Even so, boron is somewhatrelated to metalloids and also to nonmetals in period 2.It is never found in its free, pure form in nature. Although less reactive than the metalswith fewer electrons in their outer orbits, boron is usually compounded with oxygen andsodium, along with water, and in Boron, it is referred to as borax. It is also found asa hard, brittle, dark-brown substance with a metallic luster, as an amorphous powder, or asshiny-black crystals.Its melting point is 2,079°C, its boiling point is 2,550°C, and its density is 2.37 g/cm3.
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Uses
Boron has found many uses and has become an important industrial chemical. Boron is used as an alloy metal, and when combined with other metals, it imparts exceptional strength to those metals at high temperatures. It is an excellent neutron absorber used to capture neutrons in nuclear reactors to prevent a runaway fission reaction. As the boron rods are lowered into the reactor, they control the rate of fission by absorbing excess neutrons. Boron is also used as an oxygen absorber in the production of copper and other metals, Boron finds uses in the cosmetics industry (talc powder), in soaps and adhesives, and as an environmentally safe insecticide. A small amount of boron is added as a dope to silicon transistor chips to facilitate or impede the flow of current over the chip. Boron has just three valence electrons; silicon atoms have four. This dearth of one electron in boron s outer shell allows it to act as a positive hole in the silicon chip that can be filled or left vacant, thus acting as a type of switch in transistors. Many of today s electronic devices depend on these types of doped-silicon semiconductors and transistors. Boron is also used to manufacture borosilicate glass and to form enamels that provide a protective coating for steel. It is also used as medication for relief of the symptoms of arthritis. Due to boron s unique structure and chemical properties, there are still more unusual compounds to be explored. As early as 1959, boron filaments were introduced as the first of a family of high-strength, high-modulus, low-density reinforcements developed for advanced aerospace applications. A process was engineered by Avco Specialty Materials (Lowell, Massachusetts) and the U.S. Air Force to manufacture boron filaments that had high strength and high stiffness, but low density and, hence, low weight. During the interim, advanced boron fibers have been used as a reinforcement in resin-matrix composites. Boron aluminum has been used for tube-shaped truss members, for reinforcing space vehicle structures, and has also been considered as a fan blade material for turbofan jet engines.These shortcomings led to the development of silicon-carbide (SiC) fibers for some applications. The principal use of boron filaments is in the form of continuous boronepoxy pre-impregnated tape, commonly known as prepreg. Usually, the resin content is about 30–35% (weight). Boron composites have been used in military aircraft, including helicopters. In addition to aircraft, boron-epoxy composites have been used in tennis, racquetball, squash, and badminton rackets, fishing rods, skis, and golf club shafts, for improving strength and stiffness. Boron has been used in cutting and grinding tools. Boron is 30–40% harder than silicon carbide and almost twice as hard as tungsten carbide. Boron also has interesting microwave polarization properties. Research (Southern Illinois University) has shown that a single ply of boron epoxy will transmit 98.5% and reflect 0.6% of the incident microwave power when the angle between the grain and the E-field is 90°. This property has been useful in the design of spacecraft antennas and radomes. Boron is used to harden metals and as an oxygen scavenger for
copper and other metals. It is used as a reinforcing material for
composites. Boron filaments are used for lightweight but highstrength
building materials for aerospace structures, golf clubs,
and fishing rods. Amorphous boron can produce a green flare,
and is therefore useful in pyrotechnic flares. Boron is also used
in the production of borosilicate glass, which is highly resistant
to thermal shock. An alloy of boron, iron, and neodymium is
used to create a permanent magnet, known as the neodymium
magnet. These magnets are used in magnetic resonance
imaging machines, cell phones, and CD and DVD players.
Boron is also employed as a catalyst in olefin polymerization
and alcohol dehydration. Some boron compounds are used in
the production of insulating fiberglass, bleach, adhesives,
bulletproof vests, and tank armor. The principal consumption
pattern in the United States for boron is for the production of
glass products with minor usage in the production of soaps and
detergents.
