Properties And Synthesis Of Poly

2995 WordsDec 3, 201612 Pages
Properties and Synthesis of poly[p-2,5-dihydroxy-phenylenebenzobisoxazole] MANOJNA EDARA 306868401 GANNON UNIVERSITY Introduction: In recent years, poly( p-phenylene-2,6-benzobisoxazole) (PBO) fibers have become prominent in high vigor applications such as body armor,ropes and cables, and recreational equipment. The objectives of this study were to expose woven PBO body armor panels to elevated temperature and moisture, and to analyze the chemical, morphological and mechanical vicissitudes in PBO yarns extracted from the panels. A 30% decrease in yarn tensile vigor, which was correlated to transmutations in the infrared peak absorbance of key functional groups in the PBO structure, was observed during the 26 week elevated temperature/elevated moisture aging period. Substantial transmutations in chemical structure were observed via infrared spectroscopy, as well as transmutations in polymer morphology utilizing microscopy and neutron scattering. When the panels were abstracted to an ultra-dry environment for storage for 47 weeks, no further decreases in tensile vigor degradation were observed. In a follow-on study, fibers were sealed in argon-filled glass tubes and exposed to elevated temperature; less than a 4% decrease in tensile vigor was observed after 30 weeks, demonstrating that moisture is a key factor in the degradation of these fibers. Inflexible pole polymers, as poly(p-phenylene-2,6-benzoxazole) (PBO) fiber, have magnificent warm steadiness,
Open Document