Abstract
In foam cored sandwich composites, it is crucial to understand micromechanical characteristics of foam in relation with its properties to understand synergetic effects of adding nanomaterials such as CNTs. In this study, effects of CNT dispersion and distribution on cell morphology and foamability of rigid polyurethane (PU), which is directly related to microstructure and mechanical performance of overall structures were investigated. Raw and functional CNTs were added to rigid polyurethane foams up to 0.2 wt.% and their compressive strength is evaluated. The results showed that dispersion media such as PMDI with low viscosity revealed a better CNT dispersion and resulted with an enhancement of 13% in compressive strength compared to neat PU foams. This enhancement in foam core properties reflected in sandwich composites with an enhancement approximately 30% in both core shear and face ultimate strength. Hence, core shear found to be the common failure mechanism for all sandwich composites.
| Original language | English |
|---|---|
| Pages (from-to) | 187-195 |
| Number of pages | 9 |
| Journal | Composites Part A: Applied Science and Manufacturing |
| Volume | 115 |
| DOIs | |
| Publication status | Published - Dec 2018 |
Bibliographical note
Publisher Copyright:© 2018 Elsevier Ltd
Funding
The authors thank to Roketsan Missiles Inc. and ITU BAP (Project No: MYL-2017-40704) for supporting this work financially. The authors also would like to thank to M.Sc. student Beyza Bozali for performing the mechanical tests and Hasan Kaşıkçı for the support received from Likrom Inc. during the rheological tests. Also special thanks to Didem Ovalı and Deniz Köken for TGA analyses.
| Funders | Funder number |
|---|---|
| Likrom Inc. | |
| Missiles Inc. and ITU BAP | MYL-2017-40704 |
| Roketsan Missiles Inc. |
Keywords
- Carbon nanotubes
- Failure modes
- Heterogeneous nucleation
- Polyurethane
- Rheology
- Sandwich composites
- Three-point bending