Teflon relative molecular mass larger, the lower is hundreds of thousands, the higher is more than 10 million, generally millions (the degree of polymerization is 104 orders of magnitude, while polyethylene is only 103). Generally, the degree of crystallization is 90 to 95%, and the melting temperature is to ℃. CF2 units in Polytetrafluoroethylene molecules are arranged in the shape of serrated teeth. Because the radius of fluorine atoms is slightly larger than that of hydrogen, the adjacent CF2 units cannot completely follow the trans cross orientation, but form a spiral twisted chain, fluorine atoms almost cover the surface of the entire polymer chain. This molecular structure explains teflon various performance. When the temperature is lower than 19℃, a 13/6 spiral is formed; A phase change occurs at 19℃, and the molecules are slightly untied to form a 15/7 spiral.

Although the fracture of carbon-carbon bond and carbon-fluorine bond in total fluorocarbon need to absorb energy 346.94 and 484.88kJ/mol respectively, it only needs energy 171.38kJ to depolymerize polytetrafluoroethylene to generate 1mol tetrafluoroethylene. Therefore, during high-temperature cracking, Polytetrafluoroethylene is mainly depolymerized into tetrafluoroethylene. The weight loss rate (%) of polytetrafluoroethylene at 260, 370 and 420℃ is 1 × 10-4, 4 × 10-3 and 9 × 10-2 per hour respectively. It can be seen that Teflon can be used for a long time at 260℃. Due to the highly toxic by-products such as fluorine phosgene and perfluoroisobutylene produced during high-temperature cracking, special attention should be paid to safety protection and prevention of Teflon contact with open flame.

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-resistant to Aqua Regia and all organic solvents; Weather resistance-extremely long aging life in plastics; High lubrication-with extremely small friction coefficient in plastics (0.04); non-stickiness-very small in solid materials surface tension and inadhesion any substance; Non-toxic-physiological inertia; Excellent electrical performance, it is an ideal C- level insulation material. Teflon material, widely used in national defense and military industry, atomic energy, petroleum, radio, electric machinery, chemical industry and other important departments.