Why is PTFE called the plastic king?

Polytetrafluoroethylene (PTFE) is currently the most widely used fluoropolymer, which is the most resistant to chemical corrosion, has the best dielectric properties, and a wide working temperature range among plastics. It is known as the "plastic king".

                                          In 1938, Dr. Roy Plunkett of DuPont first discovered PTFE
PTFE has a series of advantages, including high temperature resistance (can be used for a long time in the temperature range of 200-260 ℃), low temperature resistance (can be used for a long time below -100 ℃), corrosion resistance (with extremely high chemical inertness), weather resistance (extremely high resistance to atmospheric aging), high lubrication (with extremely low friction coefficient), non adhesion (extremely low surface tension, not easy to adhere), good human compatibility (with good physiological inertness, non-toxic), and good electrical insulation (high insulation and not affected by temperature and humidity). These characteristics of PTFE are closely related to its molecular configuration.
The molecular structure of PTFE is similar to that of polyethylene, and it is a symmetrical and unbranched linear polymer, so the molecule does not show polarity, as shown in the following figure:

Due to the strong repulsion between non bonded fluorine atoms between molecules, the carbon chain of PTFE twists into a helical structure, while the fluorine atoms completely cover the main chain of carbon atoms, effectively preventing them from reacting with other substances. In addition, fluorocarbon bonds have a high bond energy of 466 KJ/mol, which is the highest among all chemical single bonds, making PTFE highly stable.
However, PTFE also has its own shortcomings, mainly manifested as cold flowability, high linear expansion coefficient, poor thermal conductivity, wear resistance, creep resistance, and outstanding surface non adhesiveness. These defects of PTFE limit its application to a certain extent.
China is one of the early countries to research and produce PTFE, but in the past, it mainly relied on the application of foreign technology for simple processing, with less in-depth research and overall production level and process technology are not high. With years of accumulation and development, especially in the past decade, the technical level of China's fluorine chemical industry has made rapid progress. About 20 enterprises, including Dongyue, Chenguang, Sanaifu, Juhua, and Meilan, can produce PTFE. Since PTFE has such unique properties, in which fields is it usually used?
Chemical field
PTFE does not dissolve or swell in any known liquid, so PTFE components remain unchanged in size in any corrosive medium, regardless of how long they are used. Large thin-walled containers made of PTFE are widely used in laboratories and factories that use corrosive liquids. In addition, they are also widely used in seals, pipeline linings, pumps, valves, and other applications.

                                                                        (The picture shows a seal made of PTFE)
                                                                                          Mechanical field
Regardless of the type of mechanical equipment, lubrication is required for the sliding surfaces during operation to reduce the friction coefficient, minimize wear and heat generation of the components, and ensure the normal operating capacity, accuracy, and power consumption of the mechanical equipment. The low friction coefficient and self-lubricating properties of PTFE make it widely used in the manufacture of bearings, piston rings, machine tool guides, and sealing materials. However, due to its high cost, it is usually used in precision instruments or environments that require acid and alkali resistance.

                        (The illustration shows PTFE bearings with low friction coefficient and self-cleaning properties)
                                                                                                  Electrical field
PTFE has excellent dielectric properties that are not actually affected by temperature and frequency, while also having extremely high thermal stability, making it an irreplaceable electrical insulation material, especially in high frequency, high temperature, and humid environments.
Nowadays, various forms of PTFE materials play an important role in the field of electronic and electrical insulation. PTFE glass paint cloth and glass cloth are used to make high-temperature and high-frequency insulation materials, which can be used in satellite communication and computer applications; PTFE film is used to make capacitors, as insulation layer, gasket, cable, etc. between instruments; PTFE thin-walled tubes of different diameters are used for lead out conduit, heat shrink tubing and spiral tubing, as well as insulation water intake pipes for generators.

              PTFE is used as a filling material and packaging material for cables, which has good insulation properties
                                                                                         Construction field
PTFE membrane structure is a new form of architectural structure that integrates architecture, structural mechanics, fine chemical engineering, materials science, and computer technology, and has high technological content.
By coating PTFE resin on ultrafine glass fiber fabric, PTFE membrane material is lightweight, strong, fire-resistant, and has good self-cleaning properties. It is not affected by ultraviolet radiation, fatigue resistant, torsion resistant, aging resistant, and has a long service life. It has the characteristics of high light transmittance and low heat absorption. It is precisely because of the invention of this cross era membrane material that membrane structure buildings have become modern permanent buildings.

At present, the development and application of this membrane material are relatively mature abroad, and there are many manufacturers, such as Mehler and Verseidag in Germany, Taiyoko gyo in Japan, ZTE Chemical Industry Co., Ltd., Chemfab in the United States, ObeiKan in Saudi Arabia, etc.
Medical field
PTFE has water resistance, physiological inertness, and non adhesiveness, so it is used in many tissue repair materials and artificial organ materials, such as artificial blood vessels, heart repair membranes, etc. Moreover, the biggest advantage of PTFE is that it can be disinfected by any method, and will not denature when heated under high pressure or treated with various disinfectants. Therefore, it is widely used in medical devices such as sutures, disinfectant pads, injection needles, etc.

                                                   (The picture shows an artificial blood vessel made of PTFE)
PTFE is a magical material with more potential waiting for people to explore. New material practitioners should not only be familiar with the characteristics of materials, but also maximize their features to provide us with various possibilities for a better life.