Título:
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Compared structure and morphology of nylon-12 and 10-polyurethane lamellar crystals
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Autor/a:
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Fernández Lopez, Carlos E.; Bermúdez Hermida, Marta María; Alla Bedahnane, Abdelilah; Muñoz Guerra, Sebastián; Tocha, E.; Vancso, J.
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Otros autores:
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Universitat Politècnica de Catalunya. Departament d'Enginyeria Química; Universitat Politècnica de Catalunya. POL - Polímers Industrials Avançats i Biopolímers Tecnològics |
Abstract:
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A comparative study of the structure and morphology of nylon-12 and 10-polyurethane (10-PUR) lamellar crystals, was carried out. Lamellar crystals were obtained by isothermal crystallization from diluted solution. Electron diffraction of lamellae combined with WAXS data recorded from crystal
sediments indicated that nylon-12 crystallized in either α-form or γ-form according to the solvent chosen for crystallization. The α-form was the crystal modification predominant in doubly oriented films of nylon-12 prepared by epitaxial crystallization. On the contrary, 10-PUR invariably crystallized in α-form regardless crystallization conditions. The α-form of nylon-12 and 10-PUR shared the same crystal
structure with hydrogen-bonded sheets made of antiparallel chains and stacked with progressive shifting along both b and c directions. Lamellar crystals of nylon-12 in γ-form and 10-PUR in α-form displayed similar morphological features but only the former appeared to be sensitive to temperature. Upon heating the nylon-12 crystals near to melting, the real-time WAXS analysis evidenced the occurrence of a partial γ-to-α crystal transition, and in situ AFM observations revealed the appearing of more or less regular ridges on the crystal surface. None of these changes were observed in 10-PUR crystals when subjected to similar treatment. |
Abstract:
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Peer Reviewed |
Materia(s):
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-Àrees temàtiques de la UPC::Enginyeria dels materials::Materials plàstics i polímers -Linear polyurethane -Nylon-12 -Polymer lamellar crystals -Poliuretà -Niló -Polímers cristal·lins laminars |
Derechos:
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Tipo de documento:
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Artículo - Versión publicada Artículo |
Editor:
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Elsevier
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