Graphite crystal is a hexagonal mesh planar layered structure composed of carbon elements. The bonding between layers is very weak and the distance between layers is large. Under appropriate conditions, various chemical substances such as acid, alkali and salt can be inserted into the graphite layer. And combine with carbon atoms to form a new chemical phase-graphite intercalation compound. When heated to an appropriate temperature, this interlayer compound can decompose rapidly and produce a large amount of gas, which causes graphite to expand in the axial direction into a new worm-like substance, that is, expanded graphite. This kind of unexpanded graphite intercalation compound is expandable graphite.
Application:
1. Sealing material: Compared with traditional sealing materials such as asbestos rubber, flexible graphite prepared from expanded graphite has good plasticity, resilience, lubricity, light weight, electrical conductivity, heat conduction, high temperature resistance, acid and alkali corrosion resistance, Used in aerospace, machinery, electronics, nuclear energy, petrochemical, electric power, shipbuilding, smelting and other industries;
2. Environmental protection and biomedicine: Expanded graphite obtained by high temperature expansion has rich pore structure, good adsorption performance, lipophilic and hydrophobic, good chemical stability, and reproducible reuse;
3. High-energy battery material: Use the free energy change of the interlayer reaction of expandable graphite to transform it into electric energy, which is usually used as a negative electrode in the battery;
4. Flame-retardant and fire-retardant materials:
a) Sealing strip: used for fire doors, fire glass windows, etc.;
b) Fireproof bag, plastic type fireproof blocking material, firestop ring: used to seal construction pipes, cables, wires, gas, gas pipes, etc.;
c) Flame-retardant and anti-static paint;
d) Wall insulation board;
e) Foaming agent;
f) Plastic flame retardant.
Post time: Nov-22-2021