IMPROVED PROCESS FOR COAGULATION, WASHING AND LEACHING OF SHAPED POLYBENZAZOLE ARTICLES

摘要

Articles (other than fiber) made from polybenzazole dopes are quickly washed to remove polyphosphoric acid by a combination of initially washing with an acidic liquid and second washing with a hot leaching fluid at least 60 DEG C. The process can reach acceptable residual phosphorous levels (1500 to 2000 ppm) in as little as 2 or 3 minutes.