Polyvinyl fluoride

PVF

Thermoplastic

Fixed

1.77 g · cm -3

200 ° C.

-20 ° C

Partially crystalline

0.04

Soluble in DMF

Resistant to acids, alkalis, many solvents at room temperature, cooking in carbon tetrachloride, benzene, acetone and MEK does not harm.

Polyvinyl fluoride ( PVF abbreviation ) is a fluorine -containing polymer. PVF heard as a thermoplastic material to the class of fluorine plastics. A well-known trade name of DuPont Tedlar.

Structure

Polyvinyl fluoride with the formula - [- CH2 - CHF - ] n has a chain-like structure.

In contrast, the more common polyvinylidene fluoride ( - [- CH2 - CF2 ] n ) pairs attached fluorine and hydrogen along the carbon chain.

With polyvinyl chloride ( PVC), there is also a structural relationship. Vinyl fluoride monomer is used in place of the fluorine - chlorine atom, to give vinyl chloride, which is the starting material for the production of PVC.

Properties

The bond between fluorine and carbon is much stronger than that between carbon and chlorine in the PVC, and therefore polyvinyl fluoride is chemically and physically stable than polyvinyl chloride. It can be used over a temperature range from -70 ° C. to about 110 ° C, but higher temperatures are possible ( short-term). It is stain resistant and resistant to many chemicals and plasticizers and impermeable to fats and oils. In addition, it has good weather resistance and is transparent.

Polyvinyl fluoride is from about 300-400 nm wavelength to far into the infrared transmissive to light. Refractive index n D 20 = 1:45. Flammability: burning slowly.

Applications

Polyvinyl fluoride was introduced in the early 1960s by DuPont as a film-shaped semi-finished products in the market. In addition to crystal-clear films, there are also Bezel material.

Polyvinyl fluoride is for weatherproof films ( among others in the building and electrical engineering ), bags, laminations of sheet metal in the vehicle sector and for coatings used as a tool protection. In aircraft PVF is used in so-called decorative films for surface coating in the interior of the aircraft and in the railway sector. In pneumatic PVF is used as a filter material for a vacuum filter. Because of its low gas permeability is often used for polyvinyl bag of gaseous samples.

PVF films are often used as composite films. For example, the backside coating of standard solar modules is usually made with a sheet of PVF PVF polyester composite. The film structure of decorative films is also multi-layered and usually consists of a PVF topcoat, embossed resin layer PVF backing and adhesive coating. To increase the resistance to scratches and damage and fiberglass cloth are inserted into the network often.