Electron diffraction investigation of PPTA/nylon 3T blends from shear-oriented anisotropic solutions |
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Authors: | J Brisson R Lebossé |
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Institution: | (1) Present address: Centre de Recherches en Sciences et Ingénierie des Macromolécules, Départment de Chimie Faculté des sciences et de génie Pavillon Vachon, Université Laval, G1K 7P4 Québec, Canada |
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Abstract: | Nematic solutions of PPTA and nylon 3T were prepared in H2SO4 Optical microscopy was used to ascertain the phase behaviour of the blends. In the studied concentration range, no phase separation was observed. The solutions were shear-oriented and coagulated, and the resulting samples were studied by x-ray and electron diffraction. Nylon 3T crystallised even at a low concentration, which is indicative of a phase separation. Electron diffraction investigations of the oriented samples showed that well-oriented areas, which were predominantly composed of PPTA, adjoined areas where the major component, nylon 3T, showed no orientation. The relative proportion of the unoriented areas increased with increasing nylon concentration. It was concluded that, upon coagulation, the nylon was segregated into separate phases and crystallised unoriented, whereas for PPTA, crystallisation proceeded with very little chain rearrangement therefore preserving the orientation. |
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Keywords: | Electron diffraction PPTA nylon orientation polymer blend |
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