Abstract
A lab-scale bead foaming reactor was used to investigate the foaming behavior of thermoplastic polyurethane (TPU) samples with different hard segment contents of around 39 %, 49 % and 57%. The saturation temperature, pressure, and time differently influenced the formation of hard segment crystals with different close-packed structures and sizes. Consequently, with the increase in hard segment crystallization during the saturation the heterogeneous cell nucleation was improved and the foam expansion was controlled by the stiffness of the TPU/CO2 mixture, solubility of CO2, and final shrinkage of the foamed samples. As the saturation temperature increased, the expansion ratio tended to increase with a tendency to shrink more due to the reduced crystallites content. This is while the cell density decreased due to the reduced hard segment crystallites generated during the saturation. Increase in pressure also improved the CO2 solubility and hence the expansion ratio was increased more significantly. The saturation time also influenced the amount and perfection degree of hard segment crystals. The interrelation between the crystallization behavior of the TPU bead foams and process conditions was reported using differential scanning calorimetry (DSC) and scanning electron microscope (SEM) analysis.
Original language | English |
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Title of host publication | Proceedings of the 35th International Conference of the Polymer Processing Society, PPS 2019 |
Editors | Fevzi Cakmak Cebeci, Yusuf Z. Menceloglu, Serkan Unal, Yakup Ulcer |
Publisher | American Institute of Physics Inc. |
ISBN (Electronic) | 9780735419568 |
DOIs | |
Publication status | Published - 10 Jan 2020 |
Event | 35th International Conference of the Polymer Processing Society, PPS 2019 - Cesme-Izmir, Turkey Duration: 26 May 2019 → 30 May 2019 |
Publication series
Name | AIP Conference Proceedings |
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Volume | 2205 |
ISSN (Print) | 0094-243X |
ISSN (Electronic) | 1551-7616 |
Conference
Conference | 35th International Conference of the Polymer Processing Society, PPS 2019 |
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Country/Territory | Turkey |
City | Cesme-Izmir |
Period | 26/05/19 → 30/05/19 |
Bibliographical note
Publisher Copyright:© 2020 Author(s).
Keywords
- bead foaming
- crystallization
- hard segment
- supercritical CO
- TPU