Polymers teflon

This compound is used as a refrigerant and as an aerosol propellent. It is also used to synthesize tetrafluoroethylene, which is polymerized to a heat resistant polymer (Teflon) ... 

Figure 1.7 then shows respective data for an ultrahigh free-volume and performance polymer, Teflon AF2400 of DuPont (P02 = 1140 Barrer [39]). One can recognize that... 

The most inert of all the support materials are the fluoroethylene polymers (Teflon-6, Fluoropak-80), and the chlorotrifluoroethylene polymer (Kel-F). 

Although structured experimental designs are preferred for scouting programs and process development, both trial-and-error and accidents have played a role in product development the highly successful polymer Teflon was discovered due to a laboratory accident. 

The loss is converted to heat (dissipation). For low values of 6, the losses are low so that in the limit 6 = 0, there is no loss (this is the ideal capacitor). Low values of tan 6 may be approximated as tan 6 sin 6 cos 6, where cos 6 is defined as the power factor, 6 represents the angle between the direction of the voltage and current in an alternating current. Then Power = Voltage X Current x Power Factor. The loss factor approximately equals the product of the power factor and the dielectric constant, all values taken at a frequency of 60 Hertz. In nonpolar polymers (Teflon, polyolefins, polystyrene)... 

To create a superhydrophobic surface on the ITO glass by the nanoimprint process, a 1 pm thick layer of polymer (Teflon AF) was coated on the ITO glass. Then the nanoimprint stamp was pressed against the polymer coated ITO glass under 70 mbar pressure at 150°C for 30 min. After removing the stamp, nanostructures with desired dimension can be fabricated on the device surfaces. 

Packed columns are typically made of stainless steel and have outside diameters of 1/4 or 1/8 inch and lengths of 2 to 10 feet. For applications requiring greater inertness, alternative materials have been used including glass, nickel, fluorocarbon polymers (Teflon ), and steel that is lined with glass or Teflon . Copper and aluminum are conveniently soft for easy bending, but are not recommended due to their reactivity. 

PEA Perfluoro alkoxy polymer Teflon PEA E. I. du Pont de Nemours Co. 

Figure 22.10 Structure of Teflon , a fluorocarbon polymer. Teflon is an analog of polyethylene (Section 12.2), in which the H atoms are replaced with F atoms. 

Reaction 20.4 shows the bonding together of molecules of ethylene to form larger molecules. This process, widely practiced in the chemical and petrochanical industries, is called polymerization, and the products are polymers. Many other unsaturated molecules, usually based on alkenes, undergo polymerization to produce synthetic polymers used as plastics, rubber, and fabrics. As an example, tetrafluoroethylene polymerizes as shown in Figure 20.7 to produce a polymer (Teflon) that is exceptionally resistant to heat and chemicals and that can be used to form coatings to which other materials will not stick (e.g., frying pan surfaces). 

The various carbon halides, more the province of organic chemistry than inorganic, are a logical continuation of the horizontal left-to-right trend toward greater covalent character. Not only are the discrete CX4 compounds known for all the halides, but catenation is also prevalent, one of the best examples being the polymer Teflon, characterized by long -(CF2)- chains. The chlorofluorocarbons, CF C1 , or just CFCs, are discussed in Chapter 18. 

The critical surface tension can be read from the plot. It is approximately equal to 33 mN m PVC is the easiest surface to wet as ithas the highest critical surface tension among the three polymers. Teflon, with the lowest value, is the most difficult to wet, while PS is intermediate between the two others. 

Figure 10.1 Diagram of the fluorination set-up made from fluorinated polymers (Teflon) and sintered alumina. Reproduced from reference 5 by permission of Elsevier...

Polymers are familiar products in the modern world. Nylon, one of the first polymers developed, is like an artificial silk and is used in making clothing, ropes, and sails. The fluorine-containing polymer Teflon (polytetrafluoroeth-ylene) is used in nonstick frying and baking pans. Polyvinyl cWoride (PVC) is used in food wrap, hoses, pipes, and floor tile. In all, the polymer industry is huge. It has been estimated that about half of all chemists work with polymers. Of particular interest to them are the reactions that can be used to make polymers. We will briefly survey the main types of polymerization reactions. 

---