Free technical library
Teflon. History of invention and production
Directory / The history of technology, technology, objects around us
Comments on the article
Polytetrafluoroethylene, Teflon or fluoroplast-4 (-C2F4-) n is a polymer of tetrafluoroethylene (PTFE), a plastic with rare physical and chemical properties and is widely used in technology and in everyday life.
The word "Teflon" is a registered trademark of DuPont Corporation. The generic name for the substance is "polytetrafluoroethylene" or "fluoropolymer".
Teflon coated pan
Teflon is used in the chemical, electrical and food industries, in medicine, in vehicles, for military purposes, mainly as coatings. Teflon is best known for its widespread use in the production of non-stick cookware.
This amazing plastic with unique properties was discovered by accident. In the early 1930s, General Motors (GM) developed a family of chlorofluorocarbons called freons.
Structural formula of fluoroplast-4 (polytetrafluoroethylene, teflon)
One division of GM, the refrigeration firm Frigidaire, wanted to use freon as a refrigerant instead of the less efficient and toxic ammonia and sulfur dioxide. For further development, GM turned to the well-known chemical concern DuPont, which led to the creation of a joint venture - Kinetic Chemicals. Freon-114 (tetrafluorodichloroethane), the best-seller of those times, was created in his laboratories, which was exclusively supplied by Frigidaire. In the late 1930s, DuPont began looking for an equally effective refrigerant that could be sold to other refrigeration manufacturers.
Roy Plunkett, 27, was one of the chemists working on a promising new chlorofluorocarbon. To synthesize it from hydrochloric acid and gaseous tetrafluoroethylene (TFE), Plunkett and his assistant Jack Rebock prepared about 50 kg of TFE in advance, pumped under pressure into small cylinders. To prevent the cylinders from exploding, they were stored in containers with solid carbon dioxide - "dry ice".
On April 6, 1938, Plunkett connected one of the cylinders to the reaction plant, opened the valve, but ... nothing happened. Careful inspection showed that the valve is fully functional. Gas leak? But after weighing the balloon, Plunket and Rebok found that the gas was still inside. With the greatest precautions they unscrewed the valve, and were surprised to find that the bottle was filled with white powder. Opening several more cylinders, the researchers saw that their walls were coated on the inside with a paraffin-like substance: a unique combination of conditions (high pressure and low temperature) caused the gas to polymerize, forming polytetrafluoroethylene, later called Teflon.
Subsequently, it turned out that Teflon has unique frictional properties (that is, it glides perfectly) and is extremely chemically resistant to aggressive media. It took a year to develop the technology for its production: on July 1, 1939, a patent application was filed.
And although Plunkett failed to improve the coolant, his product, along with thousands of other uses, found a place in the kitchen - as a non-stick coating for pans and pots.
Author: S.Apresov
We recommend interesting articles Section The history of technology, technology, objects around us:
▪ Powder
▪ Plastic bottle
▪ Adhesive tape
See other articles Section The history of technology, technology, objects around us.
Read and write useful comments on this article.
<< Back
Latest news of science and technology, new electronics:
Artificial leather for touch emulation
15.04.2024
In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>
Petgugu Global cat litter
15.04.2024
Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>
The attractiveness of caring men
14.04.2024
The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>
| Random news from the Archive ECG identification technology
01.03.2014
Researchers from the Canadian company Bionym, together with the University of Toronto, conducted a similar study using ECG material from 1000 people. Research has shown that heart rate identifies a person much more accurately than a face, and almost as accurately as a fingerprint. The result of this research was the Nymi electronic identifier.
The ECG identification system consists of three components: the actual heart rate, an electronic wristband and a computer, tablet or smartphone running Android, iOS, Windows or Mac OS, on which an identification application is installed.
The user needs to install the app and turn on Bluetooth on their computer or mobile device. After that, you need to put a bracelet on one hand, and then attach the other hand to it for a few seconds. The bracelet reads the ECG information and feeds it to the application, which analyzes the ECG and generates a template of unique features. After that, the application will be able to compare the recorded ECG template with the real heart rate of a person, and on this basis, authenticate it in the system.
When the user puts on the bracelet and touches it with the other hand, the device sends a signal to the application and establishes an authenticated session that lasts as long as the bracelet is worn. When the device is removed from the hand, the session is interrupted.
The bracelet is powered by a rechargeable battery charged via USB. A full charge of the battery is enough for about a week, that is, provided that the bracelet is constantly worn, it is quite capable of maintaining an authenticated session all this time.
According to Byonim, authentication is absolutely independent of the state of the heart at the current moment. The unique features that distinguish the rhythm of the heart of each person do not change if the heart rate increases, for example, after physical exertion.
ECG identification is three-factor. The application each time determines and compares not only the owner's ECG pattern, but also the model of his bracelet, as well as the device on which it was first installed. "In order to break into the system, a hacker would have to steal a specific bracelet, a specific smartphone with an app installed, and only after that he can try to reproduce the ECG pattern," explains Martin.
In addition, each wristband has a built-in hardware component that encrypts and stores the authentication keys. These keys sign all the data transmitted between the computer and the bracelet. In addition, transmitted data is encrypted to prevent it from being stolen during transmission.
Nymi also has a built-in motion sensor that can transmit gesture commands. They can be used in various contexts - for example, if you integrate the Nymi application with an automated door opening system, a certain movement of the hand with a bracelet can open the lock. By default, the device comes with a small set of available commands, but developers can create new ones.
|
Other interesting news:
▪ Computer mouse will prevent stress
▪ Friendship prolongs life
▪ New properties of black holes
▪ New neurons for your brain
▪ New OLED displays can be folded over 100000 times
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Cultivated and wild plants. Article selection
▪ article Point to someone's place. Popular expression
▪ article Who Invented the Accordion? Detailed answer
▪ Article Golden Root. Legends, cultivation, methods of application
▪ article Shoe dryer. Encyclopedia of radio electronics and electrical engineering
▪ article Kings are carried to the top. Focus Secret
Leave your comment on this article:
All languages of this page
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua
2000-2024
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese