Morphology and properties of rigid-rod poly(p-phenylene benzobisoxazole) (PBO) and stiff-chain poly(2,5(6)-benzoxazole) (ABPBO) fibres

Krause, Stephen; Haddock, Tim; Vezie, D. L.; Lenhert, P. G.; Hwang, Wen-Fang; Price, Gary E.; Helminiak, T. E.; O'Brien, Joseph F.; Adams, Walter

doi:10.1016/0032-3861(88)90297-2

Cited by 155 publications

(88 citation statements)

References 16 publications

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“…Both AFM topographic and phase images of PBO fiber surfaces exhibit an oriented fibrillar morphology that has been observed by other researchers [19,20,21]. …”

Section: Microscopysupporting

confidence: 77%

Chemical and physical characterization of poly(p-phenylene-2, 6-benzobisoxazole) fibers used in body armor

Chin¹,

Byrd²,

Forster³

et al. 2006

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Problems with the performance and durability of body armor based on poly(p-phenylene-2,6-benzobisoxazole) (PBO) fiber became apparent in the summer of 2003, when PBO-based body armor that had been manufactured less than 8 months earlier was penetrated by a bullet. Mechanical testing of the yarns taken from the penetrated vest indicated a 30 % decrease in tensile strength relative to yarns taken from new, unworn PBO-based vests of the same model. A number of analytical metrologies were used to characterize the yarns, including chemical (elemental and molecular) analysis, mechanical testing, thermal analysis and microscopy. Attenuated total reflectance (ATR) infrared analyses of the yarns revealed differences in their degree of hydrolytic degradation as determined by the presence of benzamide structures. The rank order of reduction in benzamide, which corresponds to benzamide hydrolysis, correlates with the rank order reduction in tensile strengths for these same yarns.

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“…Both AFM topographic and phase images of PBO fiber surfaces exhibit an oriented fibrillar morphology that has been observed by other researchers [19,20,21]. …”

Section: Microscopysupporting

confidence: 77%

Chemical and physical characterization of poly(p-phenylene-2, 6-benzobisoxazole) fibers used in body armor

Chin¹,

Byrd²,

Forster³

et al. 2006

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“…23 Transverse fibril dimensions in the 7-10 nm range have been reported in PBZT. 24 Likewise, SWNTs assemble into "ropes" of about 10 nm diameter.…”

Section: Resultsmentioning

confidence: 96%

Synthesis, Structure, and Properties of PBO/SWNT Composites^&

et al. 2002

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Poly(p-phenylene benzobisoxazole) (PBO) has been synthesized in the presence of singlewall carbon nanotubes (SWNTs) in poly(phosphoric acid) (PPA) using typical PBO polymerization conditions. PBO and PBO/SWNT lyotropic liquid crystalline solutions in PPA have been spun into fibers using dry-jet wet spinning. The tensile strength of the PBO/SWNT fiber containing 10 wt % SWNTs is about 50% higher than that of the control PBO fibers containing no SWNTs. The structure and morphology of these fibers have been studied.

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“…To improve this mechanical properties much higher, we have been looking into the structural formation of fiber during coagulation and found that a non-aqueous coagulant gives a different fiber structure 1 . The fiber is expected to have a higher molecular orientation with less structural inhomogeneity along the fiber axis, which has been revealed by small and wide-angle X-ray diffraction (SAXS and WAXS) techniques and high-resolution transmission electron microscope (HREM) observation [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] . Figure 1 shows the relationship between fiber modulus and the crystallite orientation of the (200) diffraction of the PBO crystal estimated by X ray, in which the three fibers show high molecular orientation to the fiber axis than other conventional fibers 19 .…”

Section: Introductionmentioning

confidence: 99%

The Effect of Non-Aqueous Coagulation in the Structure of Poly-<i>p</i>-phenylenebenzobisoxazole (PBO) Fibers

Kitagawa¹,

Sugihara²,

Tsutsumi³

2015

Sen-i Gakkaishi

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IntroductionA recent success of the development of poly-pphenylenebenzobisoxazole (PBO) fiber gives highstrength and high-modulus materials, which might be useful in such an area like an aerospace industry to replace heavy metals. To improve this mechanical properties much higher, we have been looking into the structural formation of fiber during coagulation and found that a non-aqueous coagulant gives a different fiber structure 1 . The fiber is expected to have a higher molecular orientation with less structural inhomogeneity along the fiber axis, which has been revealed by small and wide-angle X-ray diffraction (SAXS and WAXS) techniques and high-resolution transmission electron microscope (HREM) observation [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] . Figure 1 shows the relationship between fiber modulus and the crystallite orientation of the (200) diffraction of the PBO crystal estimated by X ray, in which the three fibers show high molecular orientation to the fiber axis than other conventional fibers 19 . A newly-developed ultra-high modulus PBO fiber (code name : HM+) made through such a non-aqueous coagulation process followed by a heat-treatment under tension shows 360 GPa in modulus, which value is definitely greater than that of the commercial high modulus type PBO HM fiber (280 GPa) 1 . It is noted that the HM fiber is made with aqueous coagulation before heat treatment with tension. High mechanical properties inevitably will be a reflection of such structural features of the PBO HM+ fibers. Also the fiber shows much structural difference in skin and core parts if it is compared with the commercial PBO fibers 17 .There arose another interest to see a relationship between surface and internal structures of the PBO fibers. Because the HM+ fiber has a different internal fiber structure from the viewpoint of molecular orientation especially when one look into the difference of molecular orientation of the fiber axis along the radial direction of the fiber 17 , the surface structure is inevitably more affected and shows relatively higher molecular orientation Abstract: This article concerns surface roughness of PBO fibers. Atomic force microscopy is applied to measuring the surface roughness of the PBO AS, HM and HM+ fibers. Also linear thermal expansion was measured. The reason that the surface roughness is decreased as fiber modulus increases is discussed from the viewpoint of microscopic fiber surface structure. There is a discussion in that the smoothness of fiber surface has relation with fiber modulus, molecular orientation and crystallinity of the fibers. The coefficient of thermal expansion is also measured. The PBO HM+ fiber shows a lower value (−8.7 × 10 −6 K −1 ) of coefficient of thermal expansion than that of the PBO HM.

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Morphology and properties of rigid-rod poly(p-phenylene benzobisoxazole) (PBO) and stiff-chain poly(2,5(6)-benzoxazole) (ABPBO) fibres

Cited by 155 publications

References 16 publications

Chemical and physical characterization of poly(p-phenylene-2, 6-benzobisoxazole) fibers used in body armor

Chemical and physical characterization of poly(p-phenylene-2, 6-benzobisoxazole) fibers used in body armor

Synthesis, Structure, and Properties of PBO/SWNT Composites^&

The Effect of Non-Aqueous Coagulation in the Structure of Poly-<i>p</i>-phenylenebenzobisoxazole (PBO) Fibers

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Morphology and properties of rigid-rod poly(p-phenylene benzobisoxazole) (PBO) and stiff-chain poly(2,5(6)-benzoxazole) (ABPBO) fibres

Cited by 155 publications

References 16 publications

Chemical and physical characterization of poly(p-phenylene-2, 6-benzobisoxazole) fibers used in body armor

Chemical and physical characterization of poly(p-phenylene-2, 6-benzobisoxazole) fibers used in body armor

Synthesis, Structure, and Properties of PBO/SWNT Composites&

The Effect of Non-Aqueous Coagulation in the Structure of Poly-<i>p</i>-phenylenebenzobisoxazole (PBO) Fibers

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Product

Resources

About

Synthesis, Structure, and Properties of PBO/SWNT Composites^&