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Polytetrafluoroethylene has extremely high chemical corrosion resistance. For example, when it is boiled in concentrated sulfuric acid, nitric acid, hydrochloric acid, or even in aqua regia, its weight and performance are unchanged, and it is almost insoluble in most solvents, only at 300°C. The above is slightly soluble in all alkanes (about 0.1g/100g). PTFE does not absorb moisture, is non-flammable, and is extremely stable to oxygen and ultraviolet rays, so it has excellent weather resistance. It is worth noting that polytetrafluoroethylene cannot withstand the alkali metal melted in a strong reducing atmosphere, ammonia alkali solution (alkali metal is dissolved in liquid ammonia), some fluorides (such as TFA), naphthalene sodium salt, etc. can corrode quickly Polytetrafluoroethylene products. Polytetrafluoroethylene has low dielectric constant and dielectric loss in a wide frequency range, and has high breakdown voltage, volume resistivity and arc resistance.
The radiation resistance of polytetrafluoroethylene is poor, and it degrades after being exposed to high-energy radiation, and the electrical and mechanical properties of the polymer are significantly reduced. Polytetrafluoroethylene is produced by radical polymerization of tetrafluoroethylene. Industrial polymerization is carried out under stirring in the presence of a large amount of water to disperse the heat of reaction and facilitate temperature control. The polymerization is generally carried out at 40-80°C and a pressure of 3-26 kgf/cm. Inorganic persulfate and organic peroxide can be used as initiators, or a redox initiation system can be used. 171.38kJ of heat is released during polymerization of tetrafluoroethylene per mole. Dispersion polymerization must add perfluorinated surfactants, such as perfluorooctanoic acid or its salts.