Polyacrylonitrile

• PAN

Fixed

1.18 g · cm -3 at 20 ° C.

Does not melt

Practically insoluble in water, soluble in DMSO, DMF

Polyacrylonitrile ( PAN abbreviation ) is the polymer of acrylonitrile.

Structure and properties

The polymer is hard as a pure substance, stiff, chemical-and solvent- resistant and has a melting point above the decomposition temperature. It is usually produced by radical polymerization.

Use

The main use is to copolymer fibers (" acrylic " ) for textiles, which are usually made ​​of polyacrylonitrile ( content> 85%) and polymethylmethacrylate exist. These products have been and are among the brands, for example,

• Polyacryl ® (formerly Bayer AG, today polyacryl GmbH),
• Dolan ® (formerly Hoechst AG, today Dolan GmbH),
• Orlon ® (formerly DuPont, Invista today )
• Crylor ® ( Radici Partecipazioni SpA) or formerly sold in the GDR as Wolpryla.

The fibers are usually textured and thus have a high bulk, making the fabrics have a wool-like character and are warm, soft and wrinkle-resistant. Therefore acrylic is used in sweaters, imitation furs and blankets, where it is often blended with cotton or wool, but also processed alone.

In addition, the PAN is used in further copolymers, such as with polyvinyl chloride ( PVC) for flame-resistant fibers (for example, artificial hair monofilament sold as Kanekalon ) or together with 1,3-butadiene and styrene as acrylonitrile-butadiene -styrene copolymer (ABS).

PAN is also a raw material for the production of carbon fibers. Another use is found for tensile strength, stretch-resistant synthetic ropes. PAN is used as a support layer in the membrane technology.

Thin fibers of modified PAN (esterification and further oxidation to the acid extension .. PAN -COOH) can be excited by alternating flushing with sodium hydroxide and hydrochloric acid to muscle-like contractions. The force developed is dependent on the degree of polymerization, the concentration of the flushing liquids and to the mechanical density of the fiber felt.

A disadvantage of the plastic is the formation of hydrocyanic acid from smoldering or over high heat.

Use of textile fiber

Besides some advantages, such as good dyeability, however, the textile products require compliance with some care instructions. The fiber is heat sensitive and must be laundered with a maximum of only 40 ° C and must not be ironed hot, only the level 1 Treating Dry is better to avoid. A chlorine bleach is not possible. For staining, basic, cationic dyes, such Astrazonfarbstoffe used.