teflon Basic properties of
1. Physical properties
Air aging resistance: radiation resistance and relatively low water permeability: the surface and performance are consistent after long-term exposure to the air.
Flame retardancy: the flame retardancy rating shall be below 90.
Temperature resistance: insoluble strong alkali, strong acid and organic solution.
Oxidation resistance: It can resist the corrosiveness of oxidants.
2. Physical characteristics
(1) Structural mechanical properties
Its friction resistance is very small, only 1/5 of that of high-pressure polyethylene, which is also the main feature of perfluorocarbon surface. And because the intermolecular force between fluorine and carbon chain is very low, PTFE is non viscous. Polytetrafluoroethylene maintains good structural and mechanical properties in a wide range of ambient temperatures from - 196 ℃ to 260 ℃. One of the characteristics of perfluorocarbon polymer materials is that the low temperature environment will not change brittleness.
(2) Resistance to solvent erosion and aging
Except for melted alkaline earth metal, PTFE is basically free from chemical corrosion. For example, in sulfuric acid, sodium cyanide, sulfuric acid, or even when boiling in aqua regia, the net weight and performance of the product do not change, and it is basically insoluble in every organic solvent. It can only be slightly dissolved in full ethane above 300 ℃. The polytetrafluoroethylene is not affected by moisture and is difficult to burn. It is extremely stable to oxygen and ultraviolet light, so it has excellent aging resistance.
(3) Electrical performance
The relative dielectric constant and dielectric loss of PTFE are not high in a relatively wide operating frequency range, and the breakdown field strength, surface resistivity and arc resistance are relatively high.
(4) Radiation source resistance
The radiation resistance of polytetrafluoroethylene is weak, which causes dissolution after being compared with the radiation source, and the electrical properties and structural mechanical properties of the polymer materials are significantly reduced.
3. Application
Polytetrafluoroethylene has a series of unique properties, such as wide application ambient temperature coverage (- 250~260 ℃), good chemical resistance, dielectric property, self-lubricating property and anti adhesion. In the equipment field, it can be used for self-lubricating bearings, engine pistons, framework seals, cylinder seals, etc. Self lubrication can reduce the damage and scalding of parts and reduce energy consumption. Because of its resistance to solvent erosion, it has been widely used as a chemical plant industry Rubber seals And filler.
