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PREPARATION AND CHARACTERIZATION OF POLYMER/FERROELECTRIC CERAMIC PARTICLE COMPOSITES FOR ELECTROACTIVE ACTUATION

Peng, Peng
http://rave.ohiolink.edu/etdc/view?acc_num=case1443539252

Abstract Details

, Master of Sciences, Case Western Reserve University, Macromolecular Science and Engineering.
Electroactive polymers (EAP) as actuators are recently needed in many respects. However, the high operating voltage hinders these applications. This drawback could be improved by increasing the dielectric constant while maintaining the low stiffness. Composites with efficient fillers have the capability to achieve this improvement. In this thesis, polymer/ferroelectric ceramic particles composites were designed. The functional properties such as dielectric and mechanical properties were characterized, with the use of broadband dielectric spectroscopy (BDS), tensile mechanical analysis, and actuation experiments. First, phosphoric acid-terminated POSS was synthesized and used to modify the Ba0.7Sr0.3TiO3 (BST) particles in order to make a homogeneous dispersion. Nuclear magnetic resonance (NMR) results showed that the functional POSS was successfully synthesized and the structures were just like designed. Octylphosphonic acid (OPA) was also used for the surface modification of BST particles as a comparison. Fourier transform infrared spectroscopy (FTIR) indicated that BST@OPA has been successfully synthesized. Then, the coated fillers were blended with poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) with the use of the Minilab counter-rotating twin screw extruder. Scanning electron microscope (SEM) images showed the dispersion of the fillers in the matrix. Results showed that POSS is much better than OPA as a ligand to approach a homogeneous dispersion. After the sample was properly mixed the films were made using a hot-press (temp.160 ¿C). In this step several compositions were made to give comparison. To test the dielectric properties, broadband dielectric spectroscopy (BDS) was used. In the BDS study, the relative permittivity, loss, and tand were determined. It was shown that the use of BST (Ba0.7Sr0.3TiO3) particles can lead to an increase of dielectric constant up to 4 times. Young’s moduli for the composites, obtained through compression test, were higher than the pure elastomer, indicating that the mechanical properties were stiffer. The variation in both electrical and mechanical properties still allows for electromechanical improvement. Actuation measurements were taken with the use of a Linear Variable Differential Transformer (LVDT). Aluminum was used as compliant electrodes and evaporated on the top and bottom of the films. When electric field was applied, the film expanded. The mechanically coupled LVDT will convert the rectilinear motion into a corresponding electrical signal and measure the actuation. The dynamic testing shows the electrostriction can enhance the actuation.
Lei Zhu (Advisor)
Liming Dai (Committee Member)
Alexander Jamieson (Committee Member)
Materials Science; Polymers

Recommended Citations

Citations

  • Peng, P. (2015). PREPARATION AND CHARACTERIZATION OF POLYMER/FERROELECTRIC CERAMIC PARTICLE COMPOSITES FOR ELECTROACTIVE ACTUATION [Master's thesis, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1443539252

    APA Style (7th edition)

  • Peng, Peng. PREPARATION AND CHARACTERIZATION OF POLYMER/FERROELECTRIC CERAMIC PARTICLE COMPOSITES FOR ELECTROACTIVE ACTUATION. 2015. Case Western Reserve University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1443539252.

    MLA Style (8th edition)

  • Peng, Peng. "PREPARATION AND CHARACTERIZATION OF POLYMER/FERROELECTRIC CERAMIC PARTICLE COMPOSITES FOR ELECTROACTIVE ACTUATION." Master's thesis, Case Western Reserve University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1443539252

    Chicago Manual of Style (17th edition)

case1443539252
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© 2015, some rights reserved.Creative Commons License PREPARATION AND CHARACTERIZATION OF POLYMER/FERROELECTRIC CERAMIC PARTICLE COMPOSITES FOR ELECTROACTIVE ACTUATION by Peng Peng is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.