| Abstract: | Approaches to alleviate the environmental degradation of as‐spun poly‐p‐phenylenebenzobisoxazole (PBO AS) fibers by moisture, acidic conditions, and UV–visible radiation were implemented and tested for efficacy. The general approaches tested include: extraction and neutralization of residual phosphoric acid using supercritical carbon dioxide; the use of UV–visible light blocking coatings of exfoliated graphite, carbon black, and glassy titanium dioxide; and improvement of initial fiber properties by the application of forces tending to compact the fiber microstructure. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3819–3829, 2006 |
