Polyvinyl fluoride (PVF) or –(CH₂CHF)_n– is a polymer material mainly used in the flammability-lowering coatings of airplane interiors and photovoltaic module backsheets. It is also used in raincoats and metal sheeting. Polyvinyl fluoride is a thermoplastic fluoropolymer with a repeating vinyl fluoride unit, and it is structurally very similar to polyvinyl chloride.

The PVF-based film was first commercialised in 1961 by DuPont under the name Tedlar.

The most widely used polymerizations of VF are in aqueous suspensions or emulsions. High pressures are required because of the VF volatility. The high electronegativity of fluorine makes the polymerization more difficult when compared to other vinyl halides. The polymerization temperatures range from 50 °C to 150 °C and can affect the crystallinity, melting point and branching of the product. Initiation is done by peroxides or azo compounds.

The resonance stabilization of the propagating intermediate (VF radical) is poor, which often leads to monomer reversals, branching and chain-transfer reactions. The presence of impurities greatly affects the molecular weight and thermal stability of the product, as the VF radical is highly reactive. This also limits the choice of polymerization mediums, surfactants, initiators or other additives.

The liquid VF is suspended in water and stabilized either by water-soluble polymers based on cellulose or polyvinyl alcohol. Inorganic salts can also act as stabilizers. The suspension polymerization is usually initiated by organic peroxides (eg diisopropyl peroxydicarbonate), but UV light or ionizing radiation can also be used. However, when there are no radicals present, the UV radiation decomposes the VF into acetylene and HF.

Emulsion polymerization can be done at highly reduced pressures and lower temperatures compared to suspension polymerization. The improved process control and reaction heat removal lead to increase in molecular weight, rate of reaction and yield. Fluorinated surfactants such as perfluorinated carboxylic acids maintain a high rate of reaction even after 40% conversion, they are thermally and chemically stable and their incorporation does not impair PVF properties. Other emulsifiers (fatty alcohol sulfates, alkane sulfonates etc) are not as effective.

PVF is usually converted into thin films and coatings. However, due to its hydrogen bonds and crystallinity, a temperature above 100 °C is necessary to dissolve PVF in latent solvents. The processing by melt extrusion depends on the latent solvation of PVF in highly polar solvents and its subsequent coalescence. The incorporation of additives (plasticizers, pigments, stabilizers etc.) is done by dispersion with PVF in the latent solvent. The solvent is evaporated after extrusion.

To create biaxially oriented films, the PVF dispersed in solvent must be trailed by both transverse directions and biaxial orientations, which results in higher tensile strength. The unoriented films are also slightly stretched after casting. They are more compliant and formable and exhibit higher elongation at break than the oriented films.