Calorimetric and Dielectric Investigations of Epoxy-Based Nanocomposites with Halloysite Nanotubes as Nanofillers
Epoxy nanocomposites are promising materials for industrial applications (i.e., aerospace, marine and automotive industry) due to their extraordinary mechanical and thermal properties. Here, the effect of hollow halloysite nanotubes (HNT) on an epoxy matrix (Ep) was the focus of the study. The struc...
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| Format: | Article |
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MDPI AG
2021-05-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/13/10/1634 |
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| author | Hassan Omar Glen J. Smales Sven Henning Zhi Li De-Yi Wang Andreas Schönhals Paulina Szymoniak |
| author_facet | Hassan Omar Glen J. Smales Sven Henning Zhi Li De-Yi Wang Andreas Schönhals Paulina Szymoniak |
| author_sort | Hassan Omar |
| collection | DOAJ |
| description | Epoxy nanocomposites are promising materials for industrial applications (i.e., aerospace, marine and automotive industry) due to their extraordinary mechanical and thermal properties. Here, the effect of hollow halloysite nanotubes (HNT) on an epoxy matrix (Ep) was the focus of the study. The structure and molecular mobility of the nanocomposites were investigated using a combination of X-ray scattering, calorimetry (differential (DSC) and fast scanning calorimetry (FSC)) and dielectric spectroscopy. Additionally, the effect of surface modification of HNT (polydopamine (PDA) and Fe(OH)<sub>3</sub> nanodots) was considered. For Ep/HNT, the glass transition temperature (<i>T<sub>g</sub></i>) was decreased due to a nanoparticle-related decrease of the crosslinking density. For the modified system, Ep/m-HNT, the surface modification resulted in enhanced filler–matrix interactions leading to higher <i>T<sub>g</sub></i> values than the pure epoxy in some cases. For Ep/m-HNT, the amount of interface formed between the nanoparticles and the matrix ranged from 5% to 15%. Through BDS measurements, localized fluctuations were detected as a β- and γ-relaxation, related to rotational fluctuations of phenyl rings and local reorientations of unreacted components. A combination of calorimetry and dielectric spectroscopy revealed a dynamic and structural heterogeneity of the matrix, as confirmed by two glassy dynamics in both systems, related to regions with different crosslinking densities. |
| first_indexed | 2024-03-10T11:18:43Z |
| format | Article |
| id | doaj.art-0dc9e75150d94f8ab560936993b949e7 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-10T11:18:43Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-0dc9e75150d94f8ab560936993b949e72023-11-21T20:13:33ZengMDPI AGPolymers2073-43602021-05-011310163410.3390/polym13101634Calorimetric and Dielectric Investigations of Epoxy-Based Nanocomposites with Halloysite Nanotubes as NanofillersHassan Omar0Glen J. Smales1Sven Henning2Zhi Li3De-Yi Wang4Andreas Schönhals5Paulina Szymoniak6Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, GermanyBundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, GermanyFraunhofer-Institut für Mikrostruktur von Werkstoffen und Systemen (IMWS), Walter-Hülse-Str. 1, 06120 Halle, GermanyIMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, SpainIMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, SpainBundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, GermanyBundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, GermanyEpoxy nanocomposites are promising materials for industrial applications (i.e., aerospace, marine and automotive industry) due to their extraordinary mechanical and thermal properties. Here, the effect of hollow halloysite nanotubes (HNT) on an epoxy matrix (Ep) was the focus of the study. The structure and molecular mobility of the nanocomposites were investigated using a combination of X-ray scattering, calorimetry (differential (DSC) and fast scanning calorimetry (FSC)) and dielectric spectroscopy. Additionally, the effect of surface modification of HNT (polydopamine (PDA) and Fe(OH)<sub>3</sub> nanodots) was considered. For Ep/HNT, the glass transition temperature (<i>T<sub>g</sub></i>) was decreased due to a nanoparticle-related decrease of the crosslinking density. For the modified system, Ep/m-HNT, the surface modification resulted in enhanced filler–matrix interactions leading to higher <i>T<sub>g</sub></i> values than the pure epoxy in some cases. For Ep/m-HNT, the amount of interface formed between the nanoparticles and the matrix ranged from 5% to 15%. Through BDS measurements, localized fluctuations were detected as a β- and γ-relaxation, related to rotational fluctuations of phenyl rings and local reorientations of unreacted components. A combination of calorimetry and dielectric spectroscopy revealed a dynamic and structural heterogeneity of the matrix, as confirmed by two glassy dynamics in both systems, related to regions with different crosslinking densities.https://www.mdpi.com/2073-4360/13/10/1634epoxy nanocompositeshalloysite nanotubesX-ray scatteringdifferential scanning calorimetrybroadband dielectric spectroscopyflash DSC |
| spellingShingle | Hassan Omar Glen J. Smales Sven Henning Zhi Li De-Yi Wang Andreas Schönhals Paulina Szymoniak Calorimetric and Dielectric Investigations of Epoxy-Based Nanocomposites with Halloysite Nanotubes as Nanofillers Polymers epoxy nanocomposites halloysite nanotubes X-ray scattering differential scanning calorimetry broadband dielectric spectroscopy flash DSC |
| title | Calorimetric and Dielectric Investigations of Epoxy-Based Nanocomposites with Halloysite Nanotubes as Nanofillers |
| title_full | Calorimetric and Dielectric Investigations of Epoxy-Based Nanocomposites with Halloysite Nanotubes as Nanofillers |
| title_fullStr | Calorimetric and Dielectric Investigations of Epoxy-Based Nanocomposites with Halloysite Nanotubes as Nanofillers |
| title_full_unstemmed | Calorimetric and Dielectric Investigations of Epoxy-Based Nanocomposites with Halloysite Nanotubes as Nanofillers |
| title_short | Calorimetric and Dielectric Investigations of Epoxy-Based Nanocomposites with Halloysite Nanotubes as Nanofillers |
| title_sort | calorimetric and dielectric investigations of epoxy based nanocomposites with halloysite nanotubes as nanofillers |
| topic | epoxy nanocomposites halloysite nanotubes X-ray scattering differential scanning calorimetry broadband dielectric spectroscopy flash DSC |
| url | https://www.mdpi.com/2073-4360/13/10/1634 |
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