What are Fluoropolymers

Traditionally, a fluoropol5mier or fluoroplastic is defined as a polymer consisting of carbon (C) and fluorine (F). Sometimes these are referred to as per-fluoropolymers to distinguish them from partially flu-orinated pol miers, fluoroelastomers, and other polymers that contain fluorine in their chemical structure. For example, fluorosilicone and fluoroacrylate polymers are not referred to as fluoropolymers. An example of a linear fluoropol5mier is tetrafluoroeth-ylene pol5mier (PTFE)  

A simplistic analogy would be to the chemical composition of polyethylene [(-CH2-CH2-)n] where all the hydrogen atoms have been replaced by fluorine atoms. Of course, in practice, PTFE and polyethylene are prepared in totally different ways. There are branched fluoropol5miers such as fluorinated ethylene propylene polymer (FEP)  

There is a second class of fluoropolymers called partially fluorinated in contrast to perfluorinated polymers. These molecules include hydrogen (H) in addition to fluorine and carbon. Examples include polyvinyl fluoride, pol5winylidene fluoride, ethylene tetrafluoroethylene copolymer, and ethylene chlorot-rifluoroethylene copol mier. 

Oxygen (0) and chlorine (Cl) are present in the chemical structure of some commercial fluoropolymers. Examples include perfluoroalkoxy polymer and polychlorotrifluoroethylene  

Partially fluorinated fluoropol5miers are significantly different from the perfluoropol5miers with respect to properties and processing characteristics. For example, perfluoropolymers are more thermally stable but physically less hard than partially fluorinated polymers. Both classes of fluoropolymers are discussed in Ch. 3. 

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