Preparation and Performance of (Hydroxy Modified) Poly(p-phenylene-2,6-benzobisimidazole) Resin and Fiber

Novel preparation methods for preparing (hydroxy modified) PBI monofilament fiber and PBI resin are investigated and developed by the co-polycondensation of new AA-monomer 1,2,4,5-tetraaminobenzene tetrahydrochloride (TAB•4HCl) respectively with BB type monomers 2,5-dihydroxyterephthalic acid (2,5-DHTA), hydroxyterephthalic acid (HTA) and terephthalic acid (TPA). Effects of process conditions (monomer concentration, P₂O₅content, temperature and polymerization time) on polymerization and fiber spinnability are studied systematically.