Nonstick coatings, polytetrafluoroethylene

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. 

CF2=Cp2 (tetrafluoroethene) (CF CF2) Polytetrafluoroethylene, PTFE, Teflon Nonstick coating, electrical insulation, bearings... 

Polytetrafluoroethylene is a material that s hard, heat resistant, and extremely slick. This material is used as bearings, valve seats, and (most importantly to me) nonstick coating for pots and pans. 

GF2=GF2 Tetrafluoroethylene Polytetrafluoroethylene, PTFE Teflon , nonstick coatings... 

One major use of HF is in the manufacture of fluorinated hydrocarbons. Fluorinated ethylene is used for several specialty polymers. For example, the Teflon coating on nonstick cookware is made from polytetrafluoroethylene (PTFE). This polymer is made from tetrafluoroethylene. 

Teflon (polytetrafluoroethylene) is a chemically inert polymer used to create nonstick frying pans. Polytetrafluoroethylene can be modified to form a coating, Gore-Tex, which allows the passage of water vapor, but not liquid water, and is used in many articles of clothing. Polymeric perfluorinated ethers are widely used as high performance oils and lubricants. 

Two typical slurry coating formulations are shown in Table V. Formulation A, which consists of PPS, TiCb, water, and a dispersing agent, is suitable for the production of multiple coats and for a variety of other applications. Formulation B contains polytetrafluoroethylene, and can be used to produce single coat nonstick surface coatings, or it can be applied as a top coat to a surface already coated with Formulation A. 

The most difficult-to-bond plastics family is polytetrafluoroethylene and the other fluori-nated polymers which are the Teflon-like materials. The widespread use of these polymers as coatings for cookware is, of course, based on this property of nonsticking. The conventional methods of etching which can be useful with other difificult-to-bond plastics, like polyethylene and polypropylene, simply do not work on these fluorinated polymer surfaces. Instead the surfaces must be treated with an exotic mixture of metallic sodium and naphthalene in tetrahydrofuran.( 37,i38) More recently, ionized gases (plasma treatment) have also been used successfully. Once treated the surfaces become bondable using conventional two-part liquid... 

Polytetrafluoroethylene, more commonly known as the trademarked brand name Teflon, is formed from the addition polymerization of tetrafluoroethylene. Tetrafluoroethylene, shown in Figure 25.4(c), is an analogue of ethylene in which fluorine atoms have replaced all four of the hydrogen atoms. Teflon is a very good electrical insulator, so it is commonly used to coat wires. It is probably best known, though, as a nonstick substance used to coat bakeware, frying pans, and pots. It is also used in films that can be inserted into threaded joints between metal pipes to make it easier to unscrew the connection when necessary. Because Teflon is chemically inert, it is not possible to cross-link the chains like an elastomer. The structures of some addition polymers, including the structures of their respective monomers and what they are typically used for, are summarized in Table 25.1. 

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