Name | gypsum whisker |
Synonyms | gypsum whisker |
Molecular Formula | CaSO4 |
Physical and Chemical Properties | Chemical properties fibrous or needle-like single crystal. There are two kinds of whiskers, semi-aqueous and anhydrous. The semi-aqueous matter is hydrated when it comes into contact with water, losing fibrous and acicular shape, forming anhydrite. Relative density 2.96. Melting point 1450 ℃. Heat resistance 1000 ℃. Mohs hardness 3. Tensile strength 2058 Mpa. Elastic modulus 1764 12 Mpa. |
Use | Use as a medium strength filler. In particular, the reinforcing effect of the fine-diameter fiber is the same as that of other high-performance fiber-reinforced materials. When used with plastic, can improve the tensile strength, bending strength, bending modulus of elasticity and heat distortion temperature. Can replace asbestos as friction materials, building materials, thermal insulation and cold insulation materials. Glass fibers may also be partially replaced. Aqueous whiskers can only be used at temperatures below 350 °c to avoid the release of water of crystallization. The use of temperature up to 15000 deg C, using anhydrous whiskers. |
Dihydrate gypsum is converted into α-type hemihydrate gypsum through hydrothermal reaction, and fibrous and needle-like gypsum whiskers are formed during the reaction. Pilot research development is underway.
Use | is used as a medium strength filler. In particular, the reinforcing effect of the fine-diameter fiber is the same as that of other high-performance fiber-reinforced materials. When used with plastic, can improve the tensile strength, bending strength, bending modulus of elasticity and heat distortion temperature. Can replace asbestos as friction materials, building materials, thermal insulation and cold insulation materials. Glass fibers may also be partially replaced. Aqueous whiskers can only be used at temperatures below 350 °c to avoid the release of water of crystallization. The use of temperature up to 15000 deg C, using anhydrous whiskers. |
production method | gypsum dihydrate is converted into α-hemihydrate gypsum by hydrothermal reaction, and fibrous, needle-like gypsum whiskers. Pilot study development is ongoing. |