Investigation of the three region flow curve of polymeric liquid crystals by rheo-optical methods
| Autor: | Tadahiro Asada |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
chemistry.chemical_classification
Materials science Polymers and Plastics business.industry Isotropy Shear force General Chemistry Polymer Condensed Matter::Soft Condensed Matter Physics::Fluid Dynamics Optics chemistry Rheology Shear (geology) Liquid crystal Materials Chemistry Perpendicular Light beam sense organs Composite material business |
| Zdroj: | Polymer Engineering and Science. 33:1022-1026 |
| ISSN: | 1548-2634 0032-3888 |
| DOI: | 10.1002/pen.760331603 |
| Popis: | Steady flow behavior of bulk liquid crystals and polymeric liquid crystals are summarized into a three region flow curve. Changes in the internal structure during deformation and flow were investigated by rheo-optical methods. Two different optical geometries were used. In one method, a light beam passed through perpendicular to the shear plate, and in the other method a light beam passed perpendicular to the edge of the lamina flow. The results indicate that the details of the internal texture do not necessarily appear in the rheological properties, such as viscosity, and that the molecular orientation mechanism under shear force is fundamentally different in a liquid crystal of rod-like molecules and a suspended solution of rod-like molecules. In the isotropic solution, the rod-like molecules float or are suspended in a solvent and are oriented by the flow field of the solvent fluid. However, in a liquid crystal, the torque propagates directly on the individual rod-like molecules, affecting their orientation. They flow as if it were a plastic solid. |
| Databáze: | OpenAIRE |
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