Abstract: A method for producing polymeric, e.g., polybenzimidazole (PBI) films, is provided by forming a porous membrane by coagulating a polymeric dope solution in a liquid coagulation bath containing a non-solvent alone or a mixture of a non-solvent and solvent; submerging the resulting membrane into a non-solvent bath to remove any residual solvent; placing the membrane into an acid solution, whereby the pores become filled with the acid solution; and drying the membrane to remove residual non-solvent which collapses the porous structure entrapping the acid and forming a dense film. An alternative method involves coagulating said polymer solution directly into an acid/solvent/non-solvent mixture to produce a porous membrane which imbibes the acid solution, followed by drying.

Abstract: A method for producing polybenzimidazole (PBI) fabrics for use as fuel cell or battery electrolytes by soaking a sulfonated or non-sulfonated PBI fabric in an acid solution, whereby the fibers of the fabric become swollen with the acid solution; and drying the fabric to remove residual water or methanol and concentrating the acid.

Abstract: A method for producing polybenzimidazole (PBI) paste or gel useful in a fuel cell, mixing PBI polymer with a suitable amount of an acid, which permits the polymer to dissolve and form a matrix having a gel-like or paste-like consistency at room temperature.

Abstract: Preceramic fibers are produced by dissolving a solid organosilicon preceramic polymer in a solvent to form a spinning solution containing at least seventy percent polymer solids, dry spinning and extracting solvent in the presence of a non-oxidizing gas at a temperature and pressure sufficient to vaporize solvent from the fiber, and at least one curing agent being added to the non-oxidizing gas or spinning solution, or both, to induce on-line curing of the fiber or to aid in subsequent curing of the fiber or both. The preceramic fibers are thereafter pyrolyzed to ceramic form.