Polybenzimidazole (PBI) is a high performance polymer fiber that was discovered in the 1950s and developed by the Celanese Corporation over the next decade. NASA became interested in the unique qualities of the fiber after a fire erupted aboard an Apollo spaceship in 1967, spurring them to combine forces with Celanese in the development of a line of PBI textiles.

View a second image of a Polybenzimidazole Fiber

PBI is manufactured from tetra-aminobiphenyl and diphenyl isophthalate, which undergo a dry spinning process that utilizes dimethyl acetamide as the solvent. The result is a long-chain aromatic polymer featuring recurring imidazole groups. The fibers formed from this polymer exhibit a number of highly desirable characteristics, such as no melting point and inflammability. The stiff fibers also maintain their integrity when exposed to high heat and are mildew, abrasion, and chemical resistant.

PBI fibers first became commercially available in 1983. Since that time the fibers have found wide usage in a number of areas. They are commonly utilized, for instance, in protective apparel, such as firefighter’s coats, rescue gear, space suits, and outer garments for hazardous materials workers. The fibers are also popularly included in industrial gloves and work wear, as well as race car driver uniforms. In molded plastic form, PBI is frequently utilized in brakes, gaskets, fuel cell membranes, and pump packing.