Melt-spun nanocomposite fibers reinforced with aligned tunicate nanocrystals

Redondo, Alexandre (Adolphe Merkle Institute, University of Fribourg, Fribourg, Switzerland) ; Chatterjee, Sourav (Department of Materials Science and Engineering, Unviersity of Delaware, Newark, USA) ; Brodard, Pierre (School of Engineering and Architecture (HEIA-FR), HES-SO // University of Applied Sciences Western Switzerland) ; Korley, LaShanda T. J. (Department of Materials Science and Engineering, University of Delaware, Newark, USA ; Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, USA) ; Weder, Christoph (Adolphe Merkle Institute, University of Fribourg, Fribourg, Switzerland) ; Gunkel, Ilja (Adolphe Merkle Institute, University of Fribourg, Fribourg, Switzerland) ; Steiner, Ullrich (Adolphe Merkle Institute, University of Fribourg, Fribourg, Switzerland)

The fabrication of nanocomposite films and fibers based on cellulose nanocrystals (P-tCNCs) and a thermoplastic polyurethane (PU) elastomer is reported. High-aspect-ratio P-tCNCs were isolated from tunicates using phosphoric acid hydrolysis, which is a process that affords nanocrystals displaying high thermal stability. Nanocomposites were produced by solvent casting (films) or melt-mixing in a twin-screw extruder and subsequent melt-spinning (fibers). The processing protocols were found to affect the orientation of both PU hard segments and the P-tCNCs within the PU matrix and therefore the mechanical properties. While the films were isotropic, both the polymer matrix and the P-tCNCs proved to be aligned along the fiber direction in the fibers, as shown using SAXS/WAXS, angle-dependent Raman spectroscopy, and birefringence analysis. Tensile tests reveal that fibers and films, at similar P-tCNC contents, display Young’s moduli and strain-at-break that are within the same order of magnitude, but the stress-at-break was found to be ten-times higher for fibers, conferring them a superior toughness over films.


Keywords:
Article Type:
scientifique
Faculty:
Ingénierie et Architecture
School:
HEIA-FR
Institute:
ChemTech - Institut des technologies chimiques
Date:
2019-11
Pagination:
17 p.
Published in:
Polymers
Numeration (vol. no.):
2019, vol. 11, no. 12, article no. 1912
DOI:
ISSN:
2073-4360
Appears in Collection:



 Record created 2020-03-03, last modified 2020-03-03

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