Melting-Induced Evolution of Morphology, Entanglement Density, and Ultradrawability of Solution-Crystallized Ultrahigh-Molecular-Weight Polyethylene
| Autor: | Dimitri A. Ivanov, Fotis Christakopoulos, Egor A. Bersenev, André Brem, Victor M. Litvinov, Theo A. Tervoort, Souren Grigorian |
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| Přispěvatelé: | Institut de Science des Matériaux de Mulhouse (IS2M), Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Morphology (linguistics) Polymers and Plastics Organic Chemistry 02 engineering and technology Quantum entanglement [CHIM.MATE]Chemical Sciences/Material chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Inorganic Chemistry Ultrahigh molecular weight polyethylene Chemical engineering Materials Chemistry 0210 nano-technology |
| Zdroj: | Macromolecules Macromolecules, American Chemical Society, 2021, 54 (12), pp.5683-5693. ⟨10.1021/acs.macromol.1c00667⟩ |
| ISSN: | 0024-9297 1520-5835 |
| Popis: | International audience; The melting-induced change in density of physical network junctions, which are formed by chain entanglements and network junctions due to anchoring of chain segments to crystals, is studied by 1 H NMR T 2 relaxometry for solution-and melt-crystallized ultra-high molecular weight polyethylene (UHMWPE)-sc-UH and mc-UH, respectively. The NMR results are complemented by real-time synchrotron WAXS and SAXS analyses to extract the sizes of the crystalline lamellae and inter-crystalline domains. Below the melting temperature, the network of physical junctions is denser in the amorphous phase of mc-UH than the one in sc-UH owing to lower entanglement density and smaller number of physical junctions from polymer crystals in sc-UH. However, the difference in the total density of physical junctions between mc-UH and sc-UH films decreases with decreasing crystallinity during melting. At the end of the melting trajectory, at vanishing crystallinity, the volume-average entanglement density, as characterized by the NMR method, is approximately the same in sc-and mc-UH. This indicates that the entanglement density in sc-UH films increases during melting owing to fast buildup of local chain entanglements. These entanglements are formed by segments of the same chain, neighboring chains, or the both due to a displacement of chain fragments upon lamellar thickening and due to the so-" p " that occurs locally in the amorphous domains. The increase in the entanglement density in sc-UH is additionally confirmed by solid-state drawability of sc-UH films that were annealed in the melting region but below the end of melting. The maximum draw ratio decreases and the drawing stress increases with increasing annealing temperature. |
| Databáze: | OpenAIRE |
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