[1] It was first discovered by American polymer chemist Carl Shipp Marvel in the pursuit of new materials with superior stability, retention of stiffness, and toughness at elevated temperature.

[2] However the discovery of aromatic polybenzimidazole, which shows excellent physical and chemical properties, was generally credited to Carl Shipp Marvel in the 1950s.

Its development history can be summarized in the following list:[4] PBI are usually yellow to brown solid infusible up to 400 °C (752 °F) or higher.

Data shows that PBI is a highly flame resistant material compared to common polymers.

[12] The preparation of PBI(IV) can be achieved by condensation reaction of diphenyl isophthalate (I) and 3,3’,4,4’-tetraaminodiphenyl (II) (Figure 1).

The spontaneous cyclization of the intermediately formed amino-amide (III) to PBI (IV) provided a much more stable amide linkage.

[14] The foam can also be controlled by adding high boiling point liquids such as diphenylether or cetane to the polycondensation.

Before the 1980s, the major applications of PBI were fire-blocking, thermal protective apparel, and reverse osmosis membranes.

PBI fiber is an excellent candidate for applications in severe environments due to its combination of thermal, chemical and textile properties.

[17] PBI-blended fabrics have been the preferred choice of active fire departments across the Americas and around the world for over 30 years.

The high decomposition temperature at which PBI starts to degrade is 1,300 °F (704 °C), exceeding Nomex/Kevlar blends (Nomex being at 700 °F (371 °C) and Kevlar at 1,100 °F (593 °C)), thus offering superior break-open and thermal protection.

Sulfonated partially fluorinated arylene main chain polymer exhibit good thermal and extended stability, high proton conductivities, less acid swelling, reasonable mechanical strength.

According to the Composite Materials Research Group at the University of Wyoming, PBI resin parts maintain significant tensile properties and compressive strength to 700 °F (371 °C).

However, gel PBI membranes made in the PPA Process show good stability for greater than 17,000 hours at 160 °C (320 °F).

[24] Application in direct methanol fuel cells may be also of interest because of a better selectivity water/methanol compared to existing membranes.

Wainright, Wang et al. reported that PBI doped with phosphoric acid was utilized as a high temperature fuel cell electrolyte.

Moreover, a safety garment manufacturer reported that gloves containing PBI outlasted asbestos by two to nine times with an effective cost.

[28] Gloves containing PBI fibers are softer and more supple than those made of asbestos, offering the worker greater mobility and comfort, even if the fabric becomes charred.

[dubious – discuss] Further, PBI fiber avoids the chronic toxicity problems associated with asbestos because it is processed on standard textile and glove fabricating equipment.

PBI's chemical, thermal and physical properties demonstrate that it can be a promising material as a flue gas filter fabric for coal-fired boilers.

[citation needed] It is dyeable to dark shades with basic dyes following caustic pretreatment and resistant to most chemicals.

Additional features: will not ignite or smolder (burn slowly without flame), mildew- and age-resistant, resistant to sparks and welding spatter.