PTFE - mysterious polymer
Like many breakthroughs in history, this also happened unexpectedly. When trying to obtain a new chemical to be used in the company[ap]s refrigeration systems. Under high pressure and with the help of a catalyst ( iron ) the tetrafluoroethylene gas was transformed into a polymer.
The mysterious polymer has been subjected to detailed tests which revealed its unusual properties. The resulting poly(tetrafluoroethylene) material, i.e. PTFE, has an extremely low coefficient of friction, shows very high chemical resistance (even to the famous gold dissolving royal water!), as well as high thermal resistance.
Originally used mainly in military technologies, PTFE polymer quickly spread to other industries as well, and since the 1950s it has quickly come to our homes as an indispensable friend of every cook.The first Teflon-coated pans were launched by the French company Tefal.
At the end of the 1960s, Gore was the first company to produce Teflon-coated fabric (gore-tex), thus giving rise to fabrics that are widely used today (e.g. in specialist work and sportswear).
Currently, Teflon is used in many industries, including laser printers (due to its high thermal resistance), electronics (due to its dielectric properties), medical industry (in plastic surgery, Teflon in the form of entangled carbon-soaked fibres is used to reconstruct facial bones, as well as in the manufacture of internal prostheses, such as artificial hip joint capsules).
Teflon-coated fabrics (Teflon-coated glass fibre) are widely used in the production sector, e.g. in the packaging industry (protection against sticking of heating surfaces), food and chemical industry (in the form of solid transport belts and thermal tunnel mesh), in the construction industry (Teflon sleeves are used as a cover for heating mirrors when welding window profiles). Tefloned fabrics and nets, due to their chemical-physical properties, work perfectly in the form of conveyor belts, are irreplaceable in production lines, as a material for slides, insulators, or all kinds of primers. A wide range of complementary products for machine service is also used in production, such as Teflon zone belts, cut-to-size belts, tyga tapes belts, cut foils and many others. In addition, Teflon is used in the production of glasses for glasses for better clarity, in nail varnishes, various types of sealants, lubricants, and also works well in wiper blades increasing significantly slippage on the glass, especially when the rain is not intense. Teflon is also added as a fibre component to carpets and fabrics for better dirt resistance.
In order to obtain a material with specific properties using PTFE, but at the same time meeting the requirements of working under certain conditions, the polymers are subjected to a process of modification. Among the most commonly used modifiers is PPVE, which added to poly(tetrafluoroethylene) allows to obtain PTFE TFM, the so-called "second generation" teflon. In addition, glass fibre (GF), carbon (C), graphite and brown are often used as modifiers. These modifications allow to change the properties of the polymers, e.g. as a result of PTFE glass fibre coating, Teflon coated fabrics widely used in industry are produced ( e.g. in the form of Teflon belts or Teflon tapes )- This modification strengthens Teflon, increases its resistance to frictional wear and reduces deformation under load, the combination of PTFE with carbon improves resistance to frictional wear and deformation (chemical resistance remains unchanged here, while electrical properties change), graphite addition, in turn, adds antistatic properties (reduces coefficient of friction, improves mechanical strength).These and many other modifications enhance the physico-mechanical properties of polymers, broadening their range of applications.
In 1990 it was discovered that Teflon can be cross-linked by radiation, i.e. above its melting point. This is done in an oxygen-free environment. Cross-linking of polymers is undoubtedly the most important industrial application of radiation treatment. Crosslinking of polymers, including Teflon, consists in the formation of additional chemical bonds between chains of high molecular weight molecules under ionizing radiation. As a result of this process, structures are created which are characterized by higher thermal and chemical resistance (to solvents) as well as better strength parameters in comparison to the starting materials.Polymers such as polyethylene, polystyrene, polyfluoride, polyvinyl alcohol and others may be cross-linked. On an industrial scale, the use of polyethylene radiation cross-linking accelerators is most common in the production of shrink films, wire insulation and shrink connectors.
Furthermore, it allows such polymers, including Teflon, to be reused in subsequent products before being disposed of.
The reuse of plastics is a very important aspect of rational resource management. Returning the waste to it may involve the reuse of material from mechanical recycling processes, where the waste produces new products, or the recovery of energy contained in the waste.Due to its very high calorific value (40MJ/kg), plastic waste is an excellent energy resource, as waste fractions that are not recyclable (e.g. too dirty or mixed) can be successfully used to produce electricity and heat, thus reducing the need for fuels from non-renewable sources (e.g. coal or natural gas).With this in mind, the European plastics industry is developing the "Zero plastics to landfills" programme, promoting a complete phase-out (by 2025) of plastic waste landfill and indicating that full management of this waste can be achieved across Europe provided that EU waste legislation is rigorously and fully implemented. In this context, it is particularly important to introduce a landfill ban on recycled and combustible waste in the EU, as called for by the whole plastics industry.