Molecular Formula | BN |
Molar Mass | 24.82 |
Density | 0.9-1.1 g/mL at 25 °C |
Melting Point | 2700℃ |
Boling Point | sublimes sl below 3000℃ [MER06] |
Water Solubility | Soluble in water (slightly soluble) at 20°C, and water (soluble) at 95°C. |
Solubility | Insoluble in cold water, slightly soluble in hot acid. |
Appearance | White powder |
Specific Gravity | 3.48 |
Color | White |
Merck | 14,1346 |
PH | 5-8 (100g/l, H2O, 20℃)(slurry) |
Storage Condition | no restrictions. |
Stability | Stable. Incompatible with oxidizing agents, water. |
Sensitive | Hygroscopic |
MDL | MFCD00011317 |
Physical and Chemical Properties | Character white loose powder. relative density 2.25 solubility insoluble in cold water, slightly soluble in hot acid. |
Use | Used to make refractory materials, furnace insulation materials, but also used in electronics, machinery, aviation and other industries |
Hazard Symbols | Xi - Irritant |
Risk Codes | 36/37 - Irritating to eyes and respiratory system. |
Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36 - Wear suitable protective clothing. |
UN IDs | UN1950 |
WGK Germany | 3 |
RTECS | ED7800000 |
TSCA | Yes |
HS Code | 2850 00 20 |
Hazard Class | 2.1 |
Toxicity | LD50 orally in Rabbit: > 2000 mg/kg LD50 dermal Rat > 2000 mg/kg |
Raw Materials | Nitrogen Urea Orthoboric acid Melamine Ammonia |
Reference Show more | 1. Chen Can, Yu Huitao, Feng Yiyu, Feng Wei. Polymer composites with thermal conductivity and self-healing functions [J]. Journal of Polymer Science, 2021,52(03):272-280. |
boron nitride (BN) ceramics have hexagonal and cubic structures. The crystal structure of hexagonal boron nitride has a similar graphite layered structure, showing a loose, lubricating, easy to absorb moisture, light and other properties of white powder, so also known as "white graphite". The theoretical density is 2.27g/cm3; And the Mohs hardness is 2. Hexagonal boron nitride is well-bred for electrical insulation, thermal conductivity, chemical stability; No apparent melting point, at 0. IMPa in nitrogen 3000 ° C sublimation, in the inert gas melting point of 3000 ° C, in a neutral reducing atmosphere, heat resistance to 2000 ° C, in nitrogen and argon in the use of temperature up to 2800 ° C, the stability is poor in an oxygen atmosphere, and the use temperature is 1000 ° C. Or lower. Hexagonal boron nitride does not dissolve in cold water, water boiling hydrolysis is very slow and produce a small amount of boric acid and ammonia; With weak acid and strong alkali at room temperature are not reacted, slightly soluble in hot acid, with molten sodium hydroxide, potassium hydroxide treatment can be decomposed. Hexagonal boron nitride has an expansion coefficient equivalent to that of quartz, but its thermal conductivity is 10 times higher than that of quartz. BN is both a good conductor of heat and an electrical insulator. Its breakdown voltage is 4 to 5 times that of alumina, and its dielectric constant is 1/2 of that of alumina. The performance of BN is stable under ultra high pressure, and BN is the lightest ceramic material. Cubic BN is sphalerite structure, high chemical stability, good thermal conductivity and heat resistance, and its hardness is similar to that of artificial diamond. It is an excellent abrasive material. Its most prominent advantage over diamond is that it does not react with ferrous metals at high temperatures and can be used at a temperature of 1400 °c.
Common methods for synthesis of boron nitride include boron anhydride method, boron halide method, boric acid method, Borax method, arc plasma method, etc. The boron anhydride method is the main method of industrial production of boron nitride. The commonly produced boron nitride is graphite-type Hexagonal boron nitride, which can be converted into diamond-type cubic boron nitride at high temperature (1800 ° C.) and high pressure (800MPa).
hexagonal boron nitride has a layered crystal structure similar to graphite, and has good lubricity and thermal conductivity. Hexagonal boron nitride is also a raw material for synthesizing cubic boron nitride. Cubic boron nitride has excellent physical and chemical properties, the hardness is second only to diamond. Cubic boron nitride is mainly used as advanced refractory materials, super hard wear-resistant materials, made of boron nitride processing of super hard materials, can be made into high-speed cutting tools and geological exploration, oil drilling bit. Because cubic boron nitride also has high thermal conductivity and good semiconductor characteristics, it is also a semiconductor material with high temperature, and is widely used in the fields of optoelectronics and microelectronics. In addition, boron nitride can be used in the manufacture of TiB2 /BN composite ceramics, metal forming mold release agent and metal wire drawing lubricant and high temperature coating, in the case of resistance to molten metal corrosion as a thermal enhancement additive, high temperature resistant insulating materials. Used as a semiconductor silicon doping source. In aviation and other industries, it can be used as heat shielding materials in aerospace, structural materials for atomic reactors, high-voltage high-frequency electric and plasma arc insulators.
packed in polyethylene plastic bags. 1kg net weight of each bag. Should be stored in a well-ventilated dry warehouse to prevent moisture. Transport should be packed in wooden boxes, so as not to damage moisture.