Characteristics of Teflon
PTFE is a vinyl polymer, and its structure, if not its behavior, is similar to polyethylene. It is formed from the monomer tetrafluoroethylene by vinyl free radical polymerization.
To obtain Teflon, we start with a chlorinating agent, in this case chlorine gas, and it is reacted with methane at a temperature of 450ºC. Through the action of UV light, Cl radicals will be formed, which will bind to methane to form trichloromethane.
In a second step the trichloromethane is reacted with hydrogen fluoride to give HClF2 and under heating to 800ºC, an endothermic reaction (all the previous ones are exothermic), we obtain the tetrafluoroethylene monomer and hydrochloric acid.
In the industry, PTFE is molded by ram extrusion. This makes it possible to obtain different parts (square and round bars, profiles and tubes) for subsequent machining (milling, turning, filing, etc.).
They are supplied in rolls of 950 mm wide and 33 meters long, in thicknesses of 76/90 microns and 127 microns. They are also available as self-adhesive PTFE-impregnated glass tapes.
Ptfe properties
Teflon is a registered trademark owned by The Chemours Company and refers to a family of products and not to a specific chemical marketed by the multinational. Among them are PFA (perfluoroalkoxide) resin and FEP (fluorinated ethylene-propylene) copolymer, commercially called Teflon-PFA and Teflon-FEP respectively. The following figure shows the formula of PFA (perfluoroalkoxide):
It is also a great electrical insulator and extremely flexible, is not altered by the action of light and is able to withstand temperatures from -270 °C (3 K) to 270 °C (543 K). Its best known quality is its non-stick properties.
One of the first uses of this material was in the Manhattan Project as a valve coating and as a sealant in tubes containing uranium hexafluoride (a highly reactive material).
Ptfe is toxic
APFO or C-8 is a material necessary for the adhesion of any non-stick coating to its base. The reason why the use of this substance is dangerous in Teflon is because the surface of Teflon deteriorates rapidly, it is not stable and the Teflon particles do not have the hardness to prevent the C-8 from volatilizing. While its non-stick qualities are good, its durability is not. For this reason, alternatives to Teflon have appeared: nonstick coatings that are more resistant or that are applied at very high temperatures, keeping their surface completely sealed.
There is talk of the emanation of toxic chemicals when Teflon is heated above 250º, which can kill a bird in the vicinity. APFO is also found in potato chip boxes, popcorn boxes, hamburger boxes, etc. A former DuPont chemist has claimed that food contained in these containers can absorb toxic substances. There are no studies in humans with evidence, although there are studies in rats.
Polytetrafluoroethylene applications
Teflon is a registered trademark owned by The Chemours Company and refers to a family of products and not to a specific chemical marketed by the multinational. Among them are PFA (perfluoroalkoxide) resin and FEP (fluorinated ethylene-propylene) copolymer, commercially called Teflon-PFA and Teflon-FEP respectively. The following figure shows the formula of PFA (perfluoroalkoxide):
It is also a great electrical insulator and extremely flexible, is not altered by the action of light and is able to withstand temperatures from -270 °C (3 K) to 270 °C (543 K). Its best known quality is its non-stick properties.
One of the first uses of this material was in the Manhattan Project as a valve coating and as a sealant in tubes containing uranium hexafluoride (a highly reactive material).