HIGH MODULUS FIBERS AND FILMS FROM A WHOLLY AROMATIC POLYAMIDE-IMIDE

Wholly aromatic polyamide-imide fibers and in-plane isotropic films were made from N,N prime -bis(2-chloro-4-aminophenyl)terephthalamide and pyromellitic dianhydride. The N-methylpyrrolidone solution of its precursor, poly-(amic-acid), was wet-spun into fibers, which were then imidized chemically or thermally. The chemically imidized fiber had tenacity: 12. 2 g/d and initial modulus (M//i): 1340 g/d. Films were prepared by casting. M//i of the stiffest film reached 2530 kg/mm**2.