Polyvinyl fluoride applications

The preceding discussion has to do with induced dipoles whereas, the relaxation studies deal with the motions of parts of polymer chains that have different relaxation times for orientation. Many polymers such as polyvinyl fluoride, polyvinyl chloride and nylons have permanent dipoles that may be reoriented on the application of an applied field. The response of the oriented permanent dipoles will vary with the strength of the applied field. 

PVDF belongs to the class of fluorinated ethylenes. With two fluorine atoms in the repeat unit, it contains 59.4% fluorine. The structure of the fluorinated ethylenes is shown in Figure 1. Of the four fluoroethylenes of this series, only polyvinyl fluoride (PVF), PVDF, and polytetrafluoroethyl-ene (PTFE) are commercially significant and only two i.e. PVDF and PTFE, found extensive applications as engineering plastics. 

Ebnesajjad S. Polyvinyl fluoride technology and applications of PVE. 1st ed. Elsevier 2012. 

The only known commercial producer of polyvinyl fluoride is DuPont Company. Tedlar is DuPont s trademark for oriented and unoriented films and three grades of PVF resin for special coatings applications. PVF films are tough, durable, preformed polyvinyl fluoride films that are manufactured in continuous rolls. PVF films can be oriented or nonoriented. Film thickness can range from 12.5 to 75 pm and can be treated for adherability or left untreated for release applications. 

In practice, an attempt is made to equalize the properties of the PVF films in the machine and transverse directions. The excellent properties of the films have spurred the use of polyvinyl fluoride films in numerous outdoor and indoor applications where mechanical strength is important in addition to chemical resistance, durability, and continuous-use temperature range. 

Vinyl fluoride is the monomer used to produce polyvinyl fluoride film for outdoor applications. 

Although not strictly the subject matter of this book, work is briefly reviewed next on the application of non mass spectrometric Py-GC methods in the determination of polymer structure. This information is inclnded in the hope, when necessary, that chemists will be able to adapt these methods by including a mass spectrometric detailed information on polymer structure acrylates [63, 105-107], rubbers [63, 108-110], PVC [63,111-115], aliphatic polyhydrazides [116], polyoxamides [116], polyamides [117], polyether imides [118], methacrylamide [119], aromatic aliphatic polyamides [117], polyurethanes [120], chitin graft poly(2-methyl 2-oxazolone) [121, 122], polyxylyl sulfide [123-126], epoxy resins [127], polyethylene oxalate [128], polytetrafluoroethylene [129], polyvinylidene chloride [129], polyepichlorohydrin, fluorinated ethylene-propylene copolymer [129], polyvinyl fluoride [129], polyvinylidene [129], fluoride [129], SBR copolymer [129] and styrene-isoprene copolymer [130]. 

Polymeric Membranes Economically important applications required membranes that could operate at higher pH than could CA, for which the optimum is around pH = 5. Many polymeric membranes are now available, most of which have excellent hydrolytic stabihty. Particularly prominent are polysulfone, polyvinyhdene fluoride, poly-ethersulfone, polyvinyl alcohol-polyethylene copolymers, and aciylic copolymers. 

Pasa-Jell (www.bergdahl.com/PasaJell.htm) is a proprietary chemical marketed by Semco Division, Products Research and Chemical Corp., Glendale, CA. This formulation is available either as a thixotropic paste suitable for brush application or as an immersion solution for tank treatment. Pasa-Jell 107 is a blend of mineral acids, activators, and inhibitors, thickened using inorganic agents, to permit application in localized areas. The approximate chemical constituents are 40% nitric acid, 10% combined fluorides, 10% chromic acid, and 1% couplers, and the balance is water. The immersion process requires nonmetallic tanks made of polyvinyl chloride (PVC), polyethylene, or polypropylene. A recommended mixture uses 1 1 dilution for 12 min. With the thixotropic Pasa-Jell paste, a reaction time of 10—15 min assures durable bonds. ... 

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