Abstract
In order to study the coagulation behavior of poly (p-phenylenebenzobisoxazole) (PBO)/poly (phosphoric acid) (PPA) solution in solvent-water coagulant, the transfer of PPA of PBO/PPA was investigated. The transfer of PPA from PBO/PPA into solvent-water coagulant proceeded in a diffusion process. This diffusion process was apparently divided into two stages. At the first stage of coagulation, the concentration of polymer solution and the coagulation temperature affected the rate of solvent decay. Apparent diffusion coefficient of solvent was in the range from 2.0×10-4 to 3.9×10-7 cm2/s. Activation energy obtained was about 10 kcal/mol. The concentration of polymer solution and polymer components had little influence to activation energy. At the second stage of coagulation, the concentration of polymer solution had no influence on the rate of solvent decay. Apparent diffusion coefficient was in the range from 1.2×10-7 to 1.6×10-8 cm2/s and was not influenced by the concentration of polymer solution. Activation energy was about 9.2 kcal/mol.
