Polyacrylonitril

Polyacrylonitrile (PAN) is a synthetic vinyl polymer derived from the monomer acrylonitrile. Its repeating unit is −CH2−CH(CN)−, giving the approximate formula (C3H3N)n. PAN is a thermoplastic polymer with relatively high polarity due to the nitrile groups, which impart stiffness and chemical resistance. It is produced mainly by free-radical polymerization of acrylonitrile, in bulk or in solution, and is often used as a copolymer with small amounts of other monomers to modify properties.

PAN can be processed into fibers, films, or molded parts. For fiber production, PAN is dissolved in polar organic solvents such as N,N-dimethylformamide, dimethylacetamide, or dimethyl sulfoxide, and then extruded by wet or dry-spinning to form PAN fibers. The fibers are subsequently stabilized by heating in air (roughly 200–300 °C) to form ladder-like structures, followed by carbonization at higher temperatures (about 1000–2000 °C) to yield carbon fibers. These carbon fibers are valued for high strength and low weight and are used in aerospace, automotive, and sporting goods.

Applications include textile fibers (sold under various trade names as acrylic fibers), carbon-fiber precursors, and specialized membranes for gas separation. PAN copolymers are employed to tailor properties such as processability, solubility, and thermal behavior.

Safety and handling notes: acrylonitrile monomer is hazardous, but the polymer itself is generally stable and inert under normal handling.