Modeling Structural Disorder within Single Poly(p-phenylenebenzobisoxazole) Fibers Using a Submicrometer Synchrotron Beam

Davies, Richard J.; Burghammer, Manfred

doi:10.1021/ma048209a

Cited by 15 publications

(28 citation statements)

References 27 publications

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“…A micro-focus X-ray diffraction method is a suitable apparatus to meet the above demands 24 . Figure 5 shows fiber diagrams for the three PBO fibers observed with a micro X-ray beam at ID13 in ESRF.…”

Section: Resultsmentioning

confidence: 99%

“…All the patterns from the three fibers have two maxima at an offcenter position. According to the analysis and discussion made by Riekel and Davies et al 24 , the intensity profile of the (200) diffraction depends on the configuration, the density and the distribution of the (200) crystal plane of PBO on the cross-section of the fiber. All the (200) planes of the crystal that are illuminated with a micro-focus Xray beam in the fiber don't contribute to the intensity.…”

Section: Resultsmentioning

confidence: 99%

“…A micro-focus X-ray diffraction patterns were taken on the beam line ID13 (micro-focus beam line) 24 at the European Synchrotron Radiation Facility (ESRF). The day for the measurement was on November 11, 2006 and the experimental number was IN573.…”

Section: Methodsmentioning

confidence: 99%

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The Effect of Non-Aqueous Coagulation in the Structure of Poly-p-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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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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

Kitagawa¹,

Sugihara²,

Tsutsumi³

2015

Sen-i Gakkaishi

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“…Micro-focus X-ray diffraction patterns were taken at the European Synchrotron Radiation Facility (ESRF) on the beam line ID13 (micro-focus beam line) 19,24 . The experimental identification number was IN-617 on September 3, 2007.…”

Section: Micro-focus X -Ray Diffractionmentioning

confidence: 99%

“…To prove this existence of random distribution theoretically the intensity profile for the (200) plane of the PBO crystal across the fiber is calculated on the basis of a model according to the articles of Riekel and Davies et al 21,24 . If the distribution for the (200) crystal plane is random in the fiber, the number of the plane per volume that satisfy Bragg's law is constant at any point of the fiber.…”

Section: Diffraction Profile For the (200) Of Pbo Crystal Across The mentioning

confidence: 99%

A Novel Random Preferential Orientation of the Crystal A‐axis Along the Radial Direction Confirmed on the Poly‐p‐phenylenebenzobisoxazole (PBO) Fiber Made with a Water

2015

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Rigid‐Rod Polymers

Wang¹,

Jiang²,

Adams³

2011

Encyclopedia of Polymer Science and Technology

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Pursuing high strength and high modulus polymer fibers and novel electrooptical properties have motivated much research activity in rigid‐rod polymers in the past 40 years. In this review, we examine the synthesis, structures, and properties of rigid‐rod polymers with emphasis on polybenzobisoxazoles (PBO), polybenzobisthiazoles (PBZT) and polybenzimidazoles (PBI), beginning with their solution properties, especially lyotropic liquid crystallinity. High performance fibers spun from lyotropic liquid crystalline polyphosphoric acid (PPA) solution are described. The characterization of fiber properties including mechanical, thermal, electrical, and optical properties is summarized. PBO (Zylon) and PIPD (M5) fibers were successfully commercialized in high strength applications such as body armor, ropes, cables, and recreational equipment in the last 10 years, and we discuss the possible causes of rapid degradation of some PBO fibers. The concepts of molecular composites and nanocomposites provide new applications in antiballistic materials, fire protection, athletic equipment, cables, strings, ropes, cordage, sails, multilayer circuits, and catalyst supports. Recently, rigid‐rod polymer films have drawn attention in the electrooptical fields, especially for phosphoric acid (PA)‐doped PBI membranes (Celtec MEAs) in the applications of high temperature fuel cells. Computer simulation has been employed as a powerful tool to predict the properties of the rigid‐rod polymers.

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Modeling Structural Disorder within Single Poly(p-phenylenebenzobisoxazole) Fibers Using a Submicrometer Synchrotron Beam

Cited by 15 publications

References 27 publications

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

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

A Novel Random Preferential Orientation of the Crystal A‐axis Along the Radial Direction Confirmed on the Poly‐<i>p</i>‐phenylenebenzobisoxazole (PBO) Fiber Made with a Water

Rigid‐Rod Polymers

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