PTFE sheet

5mm PTFE staircase boardIt is polymerized from tetrafluoroethylenePolymer compounds, itsstructural formulaFor - [- CF2-CF2-] n -, it has excellent propertieschemical stability、Corrosion resistancePolytetrafluoroethylene, also known as PTFE or F4, is one of the corrosion-resistant materials today. "Plastic King" is the common name for polytetrafluoroethylene, which is a type of corrosion-resistant materialplastic It is not corroded by known acids, bases, salts, or oxidants, and even aqua regia is powerless against it, hence the name Plastic King, except for molten metalssodiumandLiquid fluorineExternally, capable of handling everything elsechemicalsWidely used in various applications that require acid and alkali resistanceorganic solventSealing, high lubrication and non stickinesselectrical insulationAnd good anti-aging endurance, excellent temperature resistance (can work at a temperature of+250 ℃ to -180 ℃ for a long time). Polytetrafluoroethylene itself is not toxic to humans, butproduction processOne of the raw materials used in the wholeAmmonium fluorooctanoate(PFOA) is considered to have the potential tocarcinogeniceffect.

Temperature range of -20 to 250 ℃ (-4 to+482 ° F), allowing for sudden cooling and heating, or alternating cold and hot operations.

Pressure -0.1~6.4Mpa (Full vacuum to 64kgf/cm2)

Its thermal decomposition products at around 500 degrees Celsius include tetrafluoroethylene, hexafluoropropene, and octafluorocyclobutane, which decompose into highly corrosive fluorinated gases at high temperatures.

Its emergence has solved many problems in China's chemical, petroleum, pharmaceutical and other fields. PTFE seals, gaskets, washers, PTFE seals, and sealing gaskets are made by molding suspended polymer PTFE resin. Compared with other plastics, polytetrafluoroethylene has the characteristic of chemical corrosion resistance and has been widely used as a sealing material and filling material.

High temperature resistant working temperature up to 250 ℃.

Low temperature resistance and good mechanical toughness; Even if the temperature drops to -196 ℃, it can maintain a 5% elongation rate.

Corrosion resistance shows inertness to most chemicals and solvents, and can withstand strong acids, alkalis, water, and various organic solvents.

Climate resistance has the best aging life among plastics.

High lubrication is very low in solid materialscoefficient of friction.

Non adhesion is the smallest surface tension in solid materials, and it does not adhere to any substance. Its mechanical properties have a very low coefficient of friction, only 1/5 of polyethylene, which is an important characteristic of perfluorocarbon surfaces. Due to the extremely low intermolecular forces between fluorine carbon chains, polytetrafluoroethylene has non adhesiveness.

Non toxic and physiologically inert, as artificial blood vessels and organs implanted in the body for a long time without adverse reactions.

Polytetrafluoroethylene has low dielectric constant and dielectric loss over a wide frequency range, and high breakdown voltage, volume resistivity, and arc resistance.

The radiation resistance of polytetrafluoroethylene is poor (104 rad), and it degrades after being exposed to high-energy radiation, resulting in a significant decrease in the electrical and mechanical properties of the polymer. The application of polytetrafluoroethylene can be formed by compression or extrusion processing; It can also be made into aqueous dispersions for coating, impregnation, or fiber production. Polytetrafluoroethylene is widely used in industries such as atomic energy, aerospace, electronics, electrical engineering, chemical engineering, machinery, instruments, meters, construction, textiles, and food as high and low temperature resistant, corrosion-resistant materials, insulation materials, and anti stick coatings.

Atmospheric aging resistance: radiation resistance and low permeability: long-term exposure to the atmosphere, the surface and properties remain unchanged.

Non flammability: The oxygen limit index is below 90.

Acid and alkali resistance: insoluble in strong acids, strong bases, and organic solvents.

Antioxidant properties: capable of withstanding corrosion from strong oxidants.

Acidity and alkalinity: neutral.

The mechanical properties of polytetrafluoroethylene are relatively soft. Has very low surface energy.

Polytetrafluoroethylene (F4, PTFE) has a series of excellent performance characteristics: it can withstand high temperatures for long-term use at temperatures ranging from 200 to 260 degrees Celsius, and remains soft even at temperatures as low as -100 degrees Celsius; Corrosion resistance, able to withstand aqua regia and all organic solvents; The best aging life among climate resistant plastics; High lubrication has the smallest friction coefficient among plastics (0.04); Non sticky has the smallest surface tension among solid materials and does not adhere to any substance; Non toxic and physiologically inert; Excellent electrical performance makes it an ideal C-grade insulation material.

(1) The color of the board is the natural color of the resin.

(2) The texture should be uniform, the surface should be smooth, and there should be no defects such as cracks, bubbles, delamination, mechanical damage, knife marks, etc.

(3) Allow for slight cloud like looseness.

(4) Allow no more than one non-metallic impurity with a diameter of 0.1-0.5mm and no more than one non-metallic impurity with a diameter of 0.5-2mm on a 10 × 10cm area.(5) The density is 2.1-2.3T/m3

-(CF2-CF2) n - belongs to polymers: Polytetrafluoroethylene (PTFE) has a relatively large molecular weight, ranging from tens of thousands to over ten million, and generally several million (with a degree of polymerization on the order of 104, while polyethylene is only 103). The general crystallinity is 90-95%, and the melting temperature is 327-342 ℃. The CF2 units in polytetrafluoroethylene molecules are arranged in a zigzag shape. Due to the slightly larger radius of fluorine atoms compared to hydrogen, adjacent CF2 units cannot be oriented in a trans cross manner, but instead form a helical twisted chain, with fluorine atoms covering almost the entire surface of the polymer chain. This molecular structure explains the various properties of polytetrafluoroethylene. When the temperature is below 19 ℃, a 13/6 helix is formed; At 19 ℃, a phase transition occurs, causing the molecules to slightly unravel and form a 15/7 helix. Although the breaking of carbon carbon bonds and carbon fluorine bonds in perfluorocarbons requires energy absorption of 346.94 and 484.88 kJ/mol, respectively, the depolymerization of polytetrafluoroethylene to produce 1 mol of tetrafluoroethylene only requires energy of 171.38 kJ. Therefore, during high-temperature cracking, polytetrafluoroethylene mainly depolymerizes into tetrafluoroethylene. The weight loss rates (%) of polytetrafluoroethylene at 260, 370, and 420 ℃ are 1 × 10-4, 4 × 10-3, and 9 × 10-2 per hour, respectively. It can be seen that polytetrafluoroethylene can be used for a long time at 260 ℃. Due to the production of highly toxic byproducts such as fluorophosgene during high-temperature cracking, special attention should be paid to safety protection and prevention of polytetrafluoroethylene from coming into contact with open flames.