Nonstick coatings

Tetrafluoroethene F2C = CF2 (-CF2-CF2-) (Teflon) Nonstick coating for cooking utensils bearings gaskets and fittings... 

You are probably most familiar with Teflon as a nonstick coating for kitchen utensils (Figure 23.2). The slippery surface of Teflon-coated fry pans and muffin tins results from Teflon s extremely low coefficient of friction. 

Eluoropolymers are able to withstand moderately high temperatures and are one of the slipperiest known solids. As a result, Teflon is commonly used as a nonstick coating, as a shell for bullets, and as an ingredient in waterproof fabrics. 

Table 3.3. Supercritical Spray Benefits Silicone Nonstick Coating...

Fluorocarbons and fluoropolymers have been in commercial use for over half a century and have found their way into a diverse array of products. The members of this array are too numerous to hst but they include nonstick coatings for cookware, construction materials, carpets, textiles, paints, electronic materials, household cleaners and personal hygiene products. As fluorocarbons are expensive compared to their hydrocarbon analogues, they are chosen carefully and usually to fill a void in a product attribute that simply cannot be accommodated by another material. The attributes typically afforded by the use of fluorocarbons are repellency, lubricity, chemical and thermal inertness, and low dielectric constant, in regards to which fluorocarbons are unique among their hydrocarbon counterparts. 

The fluorine atoms in polytetra-fluoroethylene tend not to experience molecular attractions, which is why this addition polymer is used as a nonstick coating and lubricant. 

Nonstick coatings for cookware, nonstick utensils, cooking sheets for cookies... 

FEP Aqueous 280 (536) release coatings Nonstick coating, wire coating, hot... 

Not all discoveries and findings are the results of a carefully worked-out plan based on the scientific method. In fact, some important discoveries and developments have been made simply by accident. An example in chemistry is the discovery of a compound commonly known as Teflon You are probably familiar with Teflon as the nonstick coating used on pots and pans, but it has many more applications. 

Figures 19.9 and 19.10 show two unusual applications of fillers in coatings. Figure 19.9 shows a schematic diagram of the surface of metal (e.g., a pan) on which white-hot particles of stainless steel fibers are sprayed to prepare the surface for a nonstick coating. In the past, these coatings were known to have a limited durability. Durability could be increased by a change to the surface through welding the fibers to the surface.

Plunkett was curious, and when he cut open the tank, he discovered a white, waxy solid in place of the gas he expected. Today, this solid is known as Teflon, a large molecule with remarkable properties. You are probably familiar with Teflon as a nonstick coating on pots and pans, but it is also used for dentures, artificial joints and heart valves, space suits, and fuel tanks on space vehicles. 

One very interesting application for polyphenylene sulfide is in coating cookware for nonstick use (10). Excellent, scratch-resistant, nonstick coatings are obtained when a formulation containing 10 to 20% polytetrafluoroethylene is used. Ryton PPS coatings are very insoluble and nontoxic, animal feeding studies indicate. 

In houseware, fluoropolymers are applied as nonstick coatings for cookware and appliance surfaces. These applications depend on thermal and chemical resistance as well as anti-stick performance. PTFE and ETFE are chosen to insulate appliance wiring that must withstand high temperatures. 

The substance Teflon, fhe nonstick coating on many frying pans, is made from fhe C2F4 molecule. Calculafe the number of C2F4 units present in 135 g of Teflon. 

Teflon is an inert, tough, and nonflammable material that is widely used for electrical insulation, nonstick coatings for cooking utensils, and bearings for low-temperature applications. 

Hydrogen fluoride is used to manufacture a variety of fluorine-containing compounds, such as the nonstick coating on the kitchenware shown in Figure 18.8. It is an acid according to both the Arrhenius and Bronsted-Lowry definitions. 

Products with nonstick coating (PTFE), including bearings, bushings, gears, and cookware, become commercially available. 

Several important plastic polymers, including nonstick coatings and polyvinyl chloride, contain group 17 elements. 

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