PHOTODEGRADATION OF HIGH-PERFORMANCE FIBERS

Since the introduction of Nomex aramid in the early 60's, there has be en an increasing need for fibers with outstanding thermal, chemical an d mechanical properties. Many of the commercially important, high perf ormance fibers contain double and triple bonds and aromatic structures that increase thermal stability. However, this unsaturation also make s them susceptible to actinic degradation. For certain military and in dustrial applications, both thermal and light stability are important selection criteria. The comparative research on the susceptibility of high performance fibers to photodegradation is limited. Hence this stu dy investigated the effects of accelerated light exposure on the stren gth, elongation and flame resistance of Kynol novoloid, Nomex aramid a nd PBI {[poly-{2,2'-(phenylene)-5,5'-bibenzimidazole]}. Resistance to microbial (fungi) deterioration also was evaluated because high perfor mance fibers often come into contact with diversified end-use environm ents. X-ray Photoelectron Spectroscopy (XPS) was used to study the pho tochemical changes in the fibers.