Teflon

Teflon is a name we hear from our childhood as it is an important element in use in non-stick cookware utensils. Teflon is made of a chemical compound named polytetrafluoroethylene that is a synthetic fluoropolymer. It has been in use for various purposes. The discoverer of Teflon is Roy Plunkett found the same while working for DuPont in New Jersey in 1938 by accident. In the 1990s, it was found that in a case where an oxygen-free atmosphere is present and there is a possibility of radiation cross-links for polytetrafluoroethylene above the point of melting.

Introduction of Teflon

Teflon is a fluorocarbon solid because it is a high molecular weight compound. It consists of carbon and fluorine. Teflon is hydrophobic. Neither water nor water-containing substances can wet Teflon, as fluorocarbons demonstrate mitigated London dispersion forces because of the high electronegativity of fluorine.

It is in use as a non-stick coating for pans and other cookware. Teflon is non-reactive, partly due to the strength of carbon and fluorine bonds. It is often in use in containers and pipework for reactive and corrosive chemicals. If in use as a lubricant, it reduces friction, wears, and energy consumption of machinery. Teflon is commonly in use as a graft material in surgical interventions. It is also employed as a coating on catheters.

Production of Teflon

Teflon is produced by tetrafluoroethylene undergoing a free radical polymerization process. The chemical equation for the process is

\(n F_2C=CF_2 \rightarrow -(F_2C-CF_2)_n-\)

As it is necessary to have a special apparatus for preventing hot spots during the process of polymerization from triggering side reactions that are dangerous. It is due to the fact that tetrafluoroethylene can decompose to carbon and tetrafluoromethane explosively. The process starts with the hemolyzing of persulphate that gives sulphate radicals:

\([O_3SO-OSO_3]^{2-} \rightleftharpoons  2 SO_4.^-\)

The result of this reaction is the termination of the polymer using sulphate ester groups. It can create OH end-groups by hydrolysing.

As the chemical compound has a bad reputation for being solvent in almost all solutions, therefore, the process of polymerization happens in water through the emulsion. Sometimes surfactant like PFOS is in use for doing polymerization. 

Properties

• Teflon is a thermoplastic polymer. It is white solid at room temperature and has a density of about \(2.2 g/cm^3\).
• The melting point of Teflon is \(327^oC (621^oF)\), though mechanical properties degrade above 260°C 500°F\). It gains its properties from the aggregate effect of carbon and fluorine bonds like all fluorocarbons. At temperatures above \(650^oC\) to \(700^oC\), it undergoes depolymerization. The dielectric strength of Teflon is 60MV/m.
• Usually, the coefficient of friction of plastics is measured against polished steel. Its coefficient of friction is 0.05 to 0.10 and is the third-lowest of any known solid material. Its resistance to van der Waals forces is the only known surface to which a gecko cannot stick. Teflon has excellent dielectric properties.

FAQs on Teflon

Question 1: Does nonstick cookware relate to Teflon?

Answer: Non-stick cookware like frypans and saucepans, has been coated with a material called polytetrafluoroethylene i.e., PTFE, commonly known as Teflon. Teflon is a synthetic chemical that is made up of carbon and fluorine atoms. It provides a nonreactive, nonstick and almost frictionless surface. The nonstick surface makes Teflon-coated cookware convenient. They are good to use and easy to clean. Thou it requires little oil or butter, making it a healthy way to cook and fry food.

Over the past decade, the safety of nonstick cookware is under investigation. The concerns have centred on a chemical perfluorooctanoic acid. Perfluorooctanoic acid was previously in use to produce nonstick cookware but isn’t in use today. The investigations have also looked into the risks that are associated with overheating Teflon.

Question 2: What are the common applications of Teflon?

Answer: Some applications of Teflon are as follows:

• In ski bindings as a non-mechanical anti-friction device.
• Placed between fabric layers to make a waterproof, breathable fabric in outdoor apparel.
• As a fabric protector to repel stains on formal school-wear, like uniform blazers.
• As a lubricant to prevent captive insects and other arthropods from escaping.
• In use as a coating for medical and healthcare applications.