Polyakrylonitrilin

Polyakrylonitrilin, often abbreviated as PAN, is a synthetic organic polymer. Its chemical structure is based on the repeating unit of acrylonitrile. The primary characteristic of polyacrylonitrile is its high nitrogen content, which plays a crucial role in its properties and applications.

PAN is typically produced through the process of free-radical polymerization of acrylonitrile monomer. The resulting polymer is a solid material, usually appearing as a white or off-white powder or fiber. It is known for its strength, rigidity, and resistance to many chemicals and solvents. The glass transition temperature of PAN is relatively high, contributing to its thermal stability.

One of the most significant applications of polyacrylonitrile is as a precursor for carbon fiber. When heated to high temperatures in the absence of oxygen, PAN undergoes a series of chemical transformations, including cyclization and dehydrogenation, ultimately forming carbon fibers. These carbon fibers are exceptionally strong and lightweight, finding widespread use in aerospace, automotive, sporting goods, and construction industries.

Beyond its role in carbon fiber production, PAN is also used in the manufacturing of acrylic fibers for textiles, such as clothing, carpets, and upholstery, due to their softness, warmth, and resistance to sunlight and chemicals. It can also be incorporated into membranes for filtration and separation processes. The versatility of polyacrylonitrile stems from its controllable polymerization and its ability to be modified for specific end-uses.