Microstructure Organization in Para-aramid Fibers
| Autor: | James Singletary, Mohan Srinivasarao, Warren F. Knoff, M. K. Ramasubramanian, Hawthorne Davis |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
010302 applied physics
Materials science Birefringence Polymers and Plastics business.industry Physics::Optics 02 engineering and technology Radius 021001 nanoscience & nanotechnology Microstructure 01 natural sciences Graded-index fiber Aramid Optics 0103 physical sciences Perpendicular Chemical Engineering (miscellaneous) Fiber 0210 nano-technology business Refractive index |
| Zdroj: | Textile Research Journal. 70:945-950 |
| ISSN: | 1746-7748 0040-5175 |
| DOI: | 10.1177/004051750007001102 |
| Popis: | The existence of "lateral birefringence," i.e., the difference between the refractive index for light polarized parallel to the fiber radius and light polarized perpendicular to the radius in the cross-sectional plane, combined with the existence of electron diffraction contrast "bands" in longitudinal fiber sections has led to work appearing to indicate that para-aramid fibers, in particular poly(para-phenylene terephthalamide), have an almost crystallographically perfect orthotropic structure in which the hydrogen bonds are all parallel to fiber radii. Optical path difference profiles, calculated based on the proposed orthotropic structure, are in reasonable qualitative agreement with interference microscope data. Quantitatively, however, the orthotropic structure is only partially developed based on published values of the principle refractive indices. Furthermore, the degree to which this structure is developed varies with distance from the fiber axis in some fibers' types. |
| Databáze: | OpenAIRE |
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