Polyvinyl fluoride properties

Emulsifiers such as fatty alcohol sulfates, alkane sulfonates, alkali salts of fatty acids, and others have been found to be slightly to marginally effective. Fluorinated surfactants, particularly perfluorinated carboxylic acids containing seven or eight fluorine atoms, have been especially effective in maintaining a high rate of polymerization after about 40% conversion. Fluorinated surfactants are characterized by low values of critical concentration of micelle formation, They are thermally and chemically stable, and their incorporation does not impair the polyvinyl fluoride properties. 

Other fluorine-containing plastics These materials, in general, attempt to compromise between the exceptional end-use properties of p.t.f.e. and the processability of ordinary thermoplastics. Examples include polychlor-trifluorethylene, tetrafluorethylene-hexafluorpropylene copolymers (FEP resins) and polyvinylidene fluoride. Polyvinyl fluoride is available in film form (Tedlar) with excellent weathering resistance. 

PVC, another widely used polymer for wire and cable insulation, crosslinks under irradiation in an inert atmosphere. When irradiated in air, scission predominates.To make cross-linking dominant, multifunctional monomers, such as trifunctional acrylates and methacrylates, must be added. Fluoropolymers, such as copol5miers of ethylene and tetrafluoroethylene (ETFE), or polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF), are widely used in wire and cable insulations. They are relatively easy to process and have excellent chemical and thermal resistance, but tend to creep, crack, and possess low mechanical stress at temperatures near their melting points. Radiation has been found to improve their mechanical properties and crack resistance. Ethylene propylene rubber (EPR) has also been used for wire and cable insulation. When blended with thermoplastic polyefins, such as low density polyethylene (LDPE), its processibility improves significantly. The typical addition of LDPE is 10%. Ethylene propylene copolymers and terpolymers with high PE content can be cross-linked by irradiation. ... 

Fluoropolymers, such as copolymer of ethylene and tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF), are widely used in wire and cable insulations. They are relatively easy to process and have excellent chemical and thermal resistance, but tend to creep, crack and possess low mechanical stress at temperatures near their melting points. Radiation has been found to improve their mechanical properties and crack resistance.36... 

PVDF is among the few semicrystalline polymers that exhibit thermodynamic compatibility with other polymers,80 in particular with acrylic or methacrylic resins.81 The morphology, properties, and performance of these blends depend on the structure and composition of the additive polymer, as well as on the particular PVDF resin. These aspects have been studied and are reported in some detail in Reference 82. For example, polyethyl acrylate is miscible with polyvinylidene fluoride, but polyisopropyl acrylate and homologues are not. Strong dipolar interactions are important to achieve miscibility with PVDF, as suggested by the observation that polyvinyl fluoride is incompatible with polyvinylidene fluoride.83... 

PVF films exhibit high dielectric constant and a high dielectric strength.96 Typical electrical properties for standard polyvinyl fluoride films are shown along with its physical properties in Table 3.11. 

Tedlar is a tradename, property of the E.l. duPont Company for a polyvinyl fluoride polymer which is manufactured by casting in a sheet and stretching to orient the molecules. The personnel of the Elastomers Division of that company advise that Tedlar has excellent resistance to most inorganic acids, bases and salts, and to many, but by no means all, organic compounds and solvents, especially in the liquid phase. However, some solvents in the vapor phase can slowly diffuse through it. The Sauereisen Cement Co., of Pittsburgh, PA, supplies this sheet under the tradename of Sauereisen 90. 

Tedlar Polyvinyl Fluoride Film, Optical Properties, Technical Bulletin, No. E-43331, DuPont Fluoroproducts (1985)... 

The linear macromolecule of polyvinyl fluoride (PVF) is based on the monomer unit [—CHj—CHF—] . PVF which is only used industrially as a thin film, exhibits good resistance to abrasion and resists staining. It also has outstanding weathering resistance and maintains useful properties from -100 to 150°C. 

Polymers that exhibit the piezoelectric effect include polyvinyl chloride, polyvinyl fluoride, and difluor polyethylene. These polymers acquire their properties through technological processing. The thin plastic foil samples are exposed to strong electric fields and then cooled to room temperature. This process results in a polarization of the material. 

However, the curiosity-motivated research on fluoro-oleftn polymers was well rewarded and a variety of novel products tumbled out. First came plastic polyvinyl fluoride and polyvinylidene fluoride each of which had remarkable physical properties. Then Tom Ford discovered that flexible but leathery products were produced when he copolymerized vinylidene fluoride with some unsaturated monomers[3]. Hanford and Roland discovered that a copolymer of propylene with tetrafluoroethylene was rubbery and even recommended that it be cured with radiation or peroxide (Figure 2). About the same time 1 found that plastic polyethylene could be changed to a limp rubbery material by attachment of as little as 5 mol percent of trifluoromethylethylene (Figure 3)[5]. However, with the urgent pressures of the war, there wasn t enough manpower to pursue these leads. Then in the press of the post World War II industrial boom these developments were put aside. There were just too many ripe apples on the tree. 

Property Polyvinyl fluoride (PVF) (CH2-CHF) Polyvinyl-idene fluoride (CH2-CF2) Polytrifluorochloroethylene (PTFCl) (CC1F-CF2) Polytetrafluoroethylene (PTFE) (CF2 F2) ... 

Polyvinyl fluoride is considerably more weathering resistant than polyvinyl chloride. Even after 20 years of weathering, no property changes can be detected [32]. 

A number of properties have to be measured to characterize and identify each fluoropolymer resin. The basic properties of fiuoropoiymers are characterized by standard test methods (Table 5.68) published by the American Society for Testing Materials (ASTM). Five major methods specify types and define properties of fluoropolymer products there is no standard specification method for polyvinyl fluoride (PVF). This section describes each method and the associated tests. Similar documents are published by the International Standards Organization (ISO). 

Polyvinyl fluoride characterization as a resin has not been published. DuPont produces films (Tedlar ) which are specified by typical film properties (described in Ch. 13). One characteristic that has been described in a number of early patents is intrinsic or inherent viscosity to compare different grades of In an example, polyvinyl fluoride was dissolved by stirring at the reflux temperature in hot cyclohexanone and the relative viscosity R V) was measured in a bath at 144°C after 75 minutes. Time of efflux of PVF solution (Ti) and solvent (Tq) through a viscometer such as Canon-Fenske was measured and relative viscosity was calculated according to Eq. (5.17). The ratio of the natural logarithm of relative viscosity to the concentration of polyvinyl solution (C, g/dl) is called the intrinsic or inherent viscosity (in Eq. 5.18, dl/g). 

Table 6.33. Properties of Polyvinyl Fluoride Films (Tedlar ) made by DuPont Company ...

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. 

Table 8.35. Properties of Biaxially Oriented Polyvinyl Fluoride Films> i...

Certain polymers, such as polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF), possess special properties in the film form, caileApiezoelectricity and pyroelectricity. Piezoelectricity is electric polarization of a film produced by mechanical strain in some crystals. The polarization is proportional to the amount of strain and changes sign with it. The reverse is true and an electrical polarization induces a mechanical strain in piezoelectric sensors. Pyroelectricity is electric polarization of a film induced by thermal absorption in some polymer crystals. The induced polarization is proportional to the level of thermal change. These properties can be used in the manufacture of transducers, microphones, loudspeakers, pressure gauges, pickup heads, hydrophones, motion sensors, and other devices from biaxially oriented PVDF films. Table 13.37 gives the properties of a piezoelectric film of polyvinylidene fluoride. 

Polyvinyl fluoride (PVF) is generally similar to PVC, but is transparent to UV radiation and therefore has excellent weathering resistance. It is used in laminates because of this property. Its brittle temperature is very low, - 165°C. 

Tedlar Polyvinyl Fluoride, Chemical Properties, Optical Properties, and Weatherability Performance, Jechn ca Bulletin No. 234444B, DuPont Company, October 1995. 

The compatibilizer improves the mechanical properties of PE/starch, and addition of a plasticizer is actually detrimental to the finished products. Although PE is used here to demonstrate the results of this invention, results are practically the same with other combinations of polymer and compatibilizer as disclosed therein. Incorporation of compatibiHzer is easily accomplished by mechanical blending of the polymer, starch, and compatibilizer prior to extrusion. Typically, the compatibilizer is composed of the same polymer as the primary polymer itself. The polymer component of the compatibilizer may be selected from the group consisting of polyethylene, polypropylene, polystyrene, polybutylene, poly(styrene-ethyl-ene-butylene-stryrene), poly(ethylene terephthalate), polyvinyl fluoride, polyvinyl chloride, or derivatives thereof [6]. 

These four functional groups have similar properties—though alkyl iodides are the most reactive and alkyl fluorides the least. PVC (polyvinyl chloride) is one of the most widely used polymers—it has a chloro group on every other carbon atom along a linear hydrocarbon framework. Methyl iodide (Mel), on the other hand, is a dangerous carcinogen, since it reacts with DNA and can cause mutations in the genetic code. 

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