Polytetrafluoroethylene ---- raw material performance

Polytetrafluoroethylene has soft mechanical properties. Has a very low surface energy.

Polytetrafluoroethylene (F4, PTFE) has a series of excellent performance: high temperature resistance - long-term use temperature 200 ~ 260 degrees, low temperature resistance - still soft at -100 degrees; corrosion resistance - can resist aqua regia and all organic solvents; weather resistance - The best aging life in plastic; high lubrication - with the smallest coefficient of friction in plastic (0.04); non-stick - with the smallest surface tension in solid materials without adhesion to any material; non-toxic - with physiological inertia; excellent electrical properties, is the ideal C-class insulating materials, newspaper thick A layer of newspaper can block the high voltage of 1500V; smoother than ice. PTFE material, widely used in the defense industry, atomic energy, petroleum, radio, electric machinery, chemical industry and other important sectors. Products: Teflon rods, tubes, sheets, and turned sheets. Polytetrafluoroethylene is a polymer of tetrafluoroethylene. The structural formula is CF3(CF2CF2)nCF3, which was discovered in the late 1930s and put into industrial production in the 1940s. Properties The relative molecular mass of PTFE is large, ranging from hundreds of thousands to more than 10 million.

Although the breakage of carbon-carbon and carbon-fluorine bonds in perfluorocarbons requires the absorption of energy 346.94 and 484.88 kJ/mol, respectively, the depolymerization of polytetrafluoroethylene to produce 1 mol of tetrafluoroethylene requires only 171.38 kJ. Therefore, polytetrafluoroethylene mainly depolymerizes to tetrafluoroethylene when cracked at high temperatures. The weight loss rate (%) of polytetrafluoroethylene at 260, 370 and 420°C is 1×10-4.4×10-3 and 9×10-2 per hour, respectively, which shows that polytetrafluoroethylene can be used at 260°C for a long time. Since high temperature cracking also produces highly toxic byproducts such as fluorophosgene and perfluorinated isobutene, special attention should be paid to safety protection and to prevent PTFE from contact with open flame.

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