Polybenzimidazole fiber
![Replica Apollo spacesuit, Chemical Heritage Foundation temporary exhibit, 2014](/Images/godic/202502/03/Replica_Apollo_spacesuit_Front_2014_Exhibit_at_Chemical_Heritage_Foundation_DSCF04865016.jpg")
![Figure1.The synthetic scheme for polybenzimidazole.](/Images/godic/202502/03/Synthesis_for_polybenzimidazole5016.png")
![The PBI fiber is made in a serial of steps following polymerization to get PBI staple form for direct usage.](/Images/godic/202502/03/PBI_fiber_industry_synthesis_process5016.png")
![Nowadays most of the fire fighters' protective gears are made with PBI fiber](/Images/godic/202502/03/Fire_fighters_gear5016.jpg")
Polybenzimidazole (PBI, short for poly[2,2’-(m-phenylen)-5,5’-bisbenzimidazole]) fiber is a synthetic fiber with a very high melting point. It has exceptional thermal and chemical stability and does not readily ignite. It was first discovered by American polymer chemist Carl Shipp Marvel in the pursuit of new materials with superior stability, retention of stiffness, toughness at elevated temperature. Due to its high stability, polybenzimidazole is used to fabricate high-performance protective apparel such as firefighter’s gear, astronaut space suits, high temperature protective gloves, welders’ apparel and aircraft wall fabrics. In recent years, polybenzimidazole found its application as a membrane in fuel cells.