Highly-Loaded Thermoplastic Polyurethane/Lead Zirconate Titanate Composite Foams with Low Permittivity Fabricated using Expandable Microspheres
The sensitivity enhancement of piezocomposites can realize new applications. Introducing a cellular structure into these materials decreases the permittivity and thus increases their sensitivity. However, foaming of piezocomposites is challenging because of the high piezoceramic loading required. In...
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-02-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/11/2/280 |
| _version_ | 1811302878831181824 |
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| author | Gayaneh Petrossian Cameron J. Hohimer Amir Ameli |
| author_facet | Gayaneh Petrossian Cameron J. Hohimer Amir Ameli |
| author_sort | Gayaneh Petrossian |
| collection | DOAJ |
| description | The sensitivity enhancement of piezocomposites can realize new applications. Introducing a cellular structure into these materials decreases the permittivity and thus increases their sensitivity. However, foaming of piezocomposites is challenging because of the high piezoceramic loading required. In this work, heat-expandable microspheres were used to fabricate thermoplastic polyurethane (TPU)/lead zirconate titanate (PZT) composite foams with a wide range of PZT content (0 vol % to 40 vol %) and expansion ratio (1⁻4). The microstructure, thermal behavior, and dielectric properties of the foams were investigated. Composite foams exhibited a fine dispersion of PZT particles in the solid phase and a uniform cellular structure with cell sizes of 50⁻100 μm; cell size decreased with an increase in the PZT content. The total crystallinity of the composites was also decreased as the foaming degree increased. The results showed that the relative permittivity (<i>ε<sub>r</sub></i>) can be effectively decreased by an increase in the expansion ratio. A maximum of 7.7 times decrease in <i>ε<sub>r</sub></i> was obtained. An extended Yamada model to a three-phase system was also established and compared against the experimental results with a relatively good agreement. This work demonstrates a method to foam highly loaded piezocomposites with a potential to enhance the voltage sensitivity. |
| first_indexed | 2024-04-13T07:37:18Z |
| format | Article |
| id | doaj.art-ae8b23f684e84dcf84d3b284b8dbac60 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-04-13T07:37:18Z |
| publishDate | 2019-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-ae8b23f684e84dcf84d3b284b8dbac602022-12-22T02:56:05ZengMDPI AGPolymers2073-43602019-02-0111228010.3390/polym11020280polym11020280Highly-Loaded Thermoplastic Polyurethane/Lead Zirconate Titanate Composite Foams with Low Permittivity Fabricated using Expandable MicrospheresGayaneh Petrossian0Cameron J. Hohimer1Amir Ameli2Advanced Composites Laboratory, School of Mechanical and Materials Engineering, Washington State University, 2710 Crimson Way, Richland, WA 99354, USAAdvanced Composites Laboratory, School of Mechanical and Materials Engineering, Washington State University, 2710 Crimson Way, Richland, WA 99354, USAAdvanced Composites Laboratory, School of Mechanical and Materials Engineering, Washington State University, 2710 Crimson Way, Richland, WA 99354, USAThe sensitivity enhancement of piezocomposites can realize new applications. Introducing a cellular structure into these materials decreases the permittivity and thus increases their sensitivity. However, foaming of piezocomposites is challenging because of the high piezoceramic loading required. In this work, heat-expandable microspheres were used to fabricate thermoplastic polyurethane (TPU)/lead zirconate titanate (PZT) composite foams with a wide range of PZT content (0 vol % to 40 vol %) and expansion ratio (1⁻4). The microstructure, thermal behavior, and dielectric properties of the foams were investigated. Composite foams exhibited a fine dispersion of PZT particles in the solid phase and a uniform cellular structure with cell sizes of 50⁻100 μm; cell size decreased with an increase in the PZT content. The total crystallinity of the composites was also decreased as the foaming degree increased. The results showed that the relative permittivity (<i>ε<sub>r</sub></i>) can be effectively decreased by an increase in the expansion ratio. A maximum of 7.7 times decrease in <i>ε<sub>r</sub></i> was obtained. An extended Yamada model to a three-phase system was also established and compared against the experimental results with a relatively good agreement. This work demonstrates a method to foam highly loaded piezocomposites with a potential to enhance the voltage sensitivity.https://www.mdpi.com/2073-4360/11/2/280piezoelectricfunctional foampiezocompositePZTexpandable microspherespermittivity |
| spellingShingle | Gayaneh Petrossian Cameron J. Hohimer Amir Ameli Highly-Loaded Thermoplastic Polyurethane/Lead Zirconate Titanate Composite Foams with Low Permittivity Fabricated using Expandable Microspheres Polymers piezoelectric functional foam piezocomposite PZT expandable microspheres permittivity |
| title | Highly-Loaded Thermoplastic Polyurethane/Lead Zirconate Titanate Composite Foams with Low Permittivity Fabricated using Expandable Microspheres |
| title_full | Highly-Loaded Thermoplastic Polyurethane/Lead Zirconate Titanate Composite Foams with Low Permittivity Fabricated using Expandable Microspheres |
| title_fullStr | Highly-Loaded Thermoplastic Polyurethane/Lead Zirconate Titanate Composite Foams with Low Permittivity Fabricated using Expandable Microspheres |
| title_full_unstemmed | Highly-Loaded Thermoplastic Polyurethane/Lead Zirconate Titanate Composite Foams with Low Permittivity Fabricated using Expandable Microspheres |
| title_short | Highly-Loaded Thermoplastic Polyurethane/Lead Zirconate Titanate Composite Foams with Low Permittivity Fabricated using Expandable Microspheres |
| title_sort | highly loaded thermoplastic polyurethane lead zirconate titanate composite foams with low permittivity fabricated using expandable microspheres |
| topic | piezoelectric functional foam piezocomposite PZT expandable microspheres permittivity |
| url | https://www.mdpi.com/2073-4360/11/2/280 |
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