REPAIR OF POLY(P-PHENYLENE-2,6-BENZOBISOXAZOLE) (PBO) FIBER FOR BALLISTIC COMPOSITES

摘要

Poly(p-phenylene-2,6-benzobisoxazole) (PBO) fiber has a high strength, a high modulus, and isrnlight weight, which makes it a leading candidate for soft body armor and fiber reinforced plasticrncomposites. The use of PBO fiber in protective applications is limited by its mechanicalrndegradation during service. Battelle has developed a supercritical (sc)CO_2 chemical diffusionrnpost processing method to treat PBO fiber that decreases the rate of mechanical degradation andrnincreases its useable service life. The tensile data show that this repair treatment yields a 14 %rnincrease for tenacity over untreated fibers after 120 days of accelerated aging (70 ℃, 90 %RH)rnwhen using 3-glycidoxypropyldimethoxymethylsilane (GPDMS) epoxy silane as the chemicalrninfused into PBO fibers. The epoxy silane chosen demonstrated an incremental increase in fiberrnlife; with optimization, greater gains could be realized. Alternate chemicals were chosen basedrnon either having epoxy or silane functionality. Each chemical was studied using analytical,rncomputational, and functional testing to assess its potential benefits on the mechanical propertiesrnof PBO fiber. The most promising potential chemicals were EPON 828?,rnpoly(dimethylsiloxane)diglycidyl ether terminated (DMS), trimethoxy(propyl)silane (TMOPS),rn1,2-epoxybutane (EB), and 1,2-epoxy-3-phenoxypropane (PGE).