Polytetrafluoroethylene is known as the "king of plastics." It is a highly crystalline polymer of tetrafluoroethylene (TFE) monomer, a white, waxy feel thermoplastic. With other materials can not be compared to solvent resistance, chemical and low cohesive energy density, while having good thermal stability and chemical inertness, very low surface friction factor and good ductility at low temperatures. The high degree of crystallinity makes PTFE processing more difficult. PTFE is one of the best materials for corrosion resistance in the world today. Except for molten metal sodium and liquid fluorine, it is resistant to all other chemicals. It does not change when boiled in aqua regia. It can be used at temperatures from -190°C to 260°C for long periods of time. jobs.
The main features:
1, a high degree of chemical stability:
PTFE can withstand all strong acids (including aqua regia, concentrated hydrofluoric acid, concentrated hydrochloric acid, nitric acid, and hair acids) except molten alkali metals, elemental fluorine and strong fluorinated media (such as chlorine trifluoride) and sodium hydroxide above 300°C. Fuming sulfuric acid, organic acids, etc.), strong bases, strong oxidants, reducing agents, and various organic solvents.
2, a wide range of use temperature:
PTFE can be used in a wide range of -190 °C ~ 260 °C, even at -260 °C ultra-low temperature is still not brittle, but also to maintain a certain degree of flexibility.
3, prominent non-sticky:
Almost all solid materials cannot adhere to the surface, and only the surface tension of 0.02N/m or less can completely wet the surface.
4, abnormal lubrication:
Usually PTFE static friction factor (f) and load (W) between the f = 0.178W-0.5 relationship, such as high-speed, high-pressure conditions, the friction factor can be less than 0.01, is a very excellent self-lubricating material.
5, excellent electrical insulation properties:
PTFE is a highly non-polar material with excellent dielectric properties and high resistance.
6, excellent anti-aging properties and radiation resistance:
PTFE has extremely high protection against all kinds of radiation.
7, excellent thermal stability:</span>
The melting point of PTFE is 327°C, which is higher than other common polymers. It has extremely valuable incombustibility.
8, minimal water absorption:
The water absorption of PTFE is generally about 0.001% to 0.005%, and its permeability is low.
PTFE has the best chemical resistance, so it is used most in anticorrosive materials and has a wide range of applications; PTFE has excellent electrical properties and is therefore used as an insulating material in the electrical and electronic industry; PTFE has a low friction factor and wear resistance. Good performance, so the production of wear-resistant materials, sliding parts and seals in the machinery industry.
1, anti-corrosion materials
1) Corrosion-resistant pipes and fittings: ducts, pipe connections, feed pipes, discharge pipes, wire flexible bushings, etc.
2) Chemical plants: Heat exchangers, distillation equipment (columns, towers, heat exchangers, tanks, valves, elbows, tees, etc.).
3) Filter material: electrolytic diaphragm, gas dialysis membrane, oil-water separation membrane, etc.