Engineering topics
Publications and source records attributed to Leal, J. R..
Gentle precisely controlled process is used to draw polybenzimidazole (PBI) fibers to denier as low as 0.17 per fiber. Yarns of lightweight fibers could be useful in applications where lightweight textiles must withstand high temperatures, corrosion, or radiation.
A study to determine the feasibility of preparing ultralow denier polybenzimidazole (PBI) yarns was undertaken. Conditions that presently yield multifilament yarns with bundle deniers ranging from 75 to 15,000 were used as a baseline. From this starting point, process parameters were identified that give five filament yarns with yarn densiers as low as 0.80. Physical properties from such ultralow denier yarns were at levels that would permit subsequent fabrication into fabrics.
Particular attention is given to polybenzimidazoles derived from the condensation of tetraaminobiphenyl and diphenylisophthalate. The polybenzimidazoles can be prepared by the condensation of equimolar amounts of the monomers in the absence of solvent. However, the polymerization has also been carried out in a variety of solvents. The polybenzimidazoles have excellent technical possibilities. These possibilities have currently not yet been commercially realized.