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Rheology and 3D Printability of Percolated Graphene–Polyamide-6 Composites

Graphene–polyamide-6 (PA6) composites with up to 17.0%·w/w graphene content were prepared via melt mixing. Oscillatory rheometry revealed that the dynamic viscoelastic properties of PA6 decreased with the addition of 0.1%·w/w graphene but increased when the graphene content was increased to 6.0%·w/w...

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Autores principales: Lee, Kok Peng Marcian, Brandt, Milan, Shanks, Robert, Daver, Fugen
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7565563/
https://www.ncbi.nlm.nih.gov/pubmed/32899316
http://dx.doi.org/10.3390/polym12092014
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author Lee, Kok Peng Marcian
Brandt, Milan
Shanks, Robert
Daver, Fugen
author_facet Lee, Kok Peng Marcian
Brandt, Milan
Shanks, Robert
Daver, Fugen
author_sort Lee, Kok Peng Marcian
collection PubMed
description Graphene–polyamide-6 (PA6) composites with up to 17.0%·w/w graphene content were prepared via melt mixing. Oscillatory rheometry revealed that the dynamic viscoelastic properties of PA6 decreased with the addition of 0.1%·w/w graphene but increased when the graphene content was increased to 6.0%·w/w and higher. Further analysis indicated that the rheological percolation threshold was between 6.0 and 10.0%·w/w graphene. The Carreau–Yasuda model was used to describe the complex viscosity of the materials. Capillary rheometry was applied to assess the steady shear rheology of neat PA6 and the 17.0%·w/w graphene–PA6 composite. High material viscosity at low shear rates coupled with intense shear-thinning in the composite highlighted the importance of selecting the appropriate rheological characterisation methods, shear rates and rheological models when assessing the 3D printability of percolated graphene–polymer composites for material extrusion (ME). A method to predict the printability of an ME filament feedstock, based on fundamental equations describing material flow through the printer nozzle, in the form of a printing envelope, was developed and verified experimentally. It was found that designing filaments with steady shear viscosities of approximately 15% of the maximum printable viscosity for the desired printing conditions will be advantageous for easy ME processing.
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spelling pubmed-75655632020-10-29 Rheology and 3D Printability of Percolated Graphene–Polyamide-6 Composites Lee, Kok Peng Marcian Brandt, Milan Shanks, Robert Daver, Fugen Polymers (Basel) Article Graphene–polyamide-6 (PA6) composites with up to 17.0%·w/w graphene content were prepared via melt mixing. Oscillatory rheometry revealed that the dynamic viscoelastic properties of PA6 decreased with the addition of 0.1%·w/w graphene but increased when the graphene content was increased to 6.0%·w/w and higher. Further analysis indicated that the rheological percolation threshold was between 6.0 and 10.0%·w/w graphene. The Carreau–Yasuda model was used to describe the complex viscosity of the materials. Capillary rheometry was applied to assess the steady shear rheology of neat PA6 and the 17.0%·w/w graphene–PA6 composite. High material viscosity at low shear rates coupled with intense shear-thinning in the composite highlighted the importance of selecting the appropriate rheological characterisation methods, shear rates and rheological models when assessing the 3D printability of percolated graphene–polymer composites for material extrusion (ME). A method to predict the printability of an ME filament feedstock, based on fundamental equations describing material flow through the printer nozzle, in the form of a printing envelope, was developed and verified experimentally. It was found that designing filaments with steady shear viscosities of approximately 15% of the maximum printable viscosity for the desired printing conditions will be advantageous for easy ME processing. MDPI 2020-09-03 /pmc/articles/PMC7565563/ /pubmed/32899316 http://dx.doi.org/10.3390/polym12092014 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Lee, Kok Peng Marcian
Brandt, Milan
Shanks, Robert
Daver, Fugen
Rheology and 3D Printability of Percolated Graphene–Polyamide-6 Composites
title Rheology and 3D Printability of Percolated Graphene–Polyamide-6 Composites
title_full Rheology and 3D Printability of Percolated Graphene–Polyamide-6 Composites
title_fullStr Rheology and 3D Printability of Percolated Graphene–Polyamide-6 Composites
title_full_unstemmed Rheology and 3D Printability of Percolated Graphene–Polyamide-6 Composites
title_short Rheology and 3D Printability of Percolated Graphene–Polyamide-6 Composites
title_sort rheology and 3d printability of percolated graphene–polyamide-6 composites
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7565563/
https://www.ncbi.nlm.nih.gov/pubmed/32899316
http://dx.doi.org/10.3390/polym12092014
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