scholarly journals Fabrication of Piezoelectric PVDF/PAR Composites Using a Sheath-Core Fiber Method

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2214
Author(s):  
Min Hong Jeon ◽  
Yu Rim Lee ◽  
Hyeon Soo Lim ◽  
Jong Sung Won ◽  
Seung Goo Lee
Keyword(s):  
Vinylidene Fluoride ◽  
Piezoelectric Properties ◽  
Testing Machine ◽  
X Ray Diffraction ◽  
Composite Surface ◽  
Fiber Assembly ◽  
Universal Testing ◽  
Poly Vinylidene Fluoride ◽  
Core Fiber ◽  
Growing Conditions

We report the preparation of sheath-core type fibers made from poly(vinylidene fluoride) (PVDF) and polyarylate (PAR) using melt conjugate spinning to fabricate piezolectric composites. The morphology of this sheath-core fiber was determined through scanning electron microscopy. Subsequently, by the compression molding of the PVDF/PAR sheath-core fiber assembly, we fabricated PVDF/PAR composites exhibiting piezoelectric properties. For enhancing the piezoelectric properties, we increased the concentration of PVDF β-crystalline phase in the PVDF/PAR composite through poling post-treatments. The resulting crystal structure of PVDF was confirmed through infrared spectroscopy and X-ray diffraction. A universal testing machine was employed to measure the tensile properties of the PVDF/PAR composites. Finally, through a hydrothermal growing method, ZnO was coated on the composite surface to enhance the piezoelectric properties, which were subsequently optimized by varying the hydrothermal growing conditions.

scholarly journals Preparation of PVDF/PAR Composites with Piezoelectric Properties by Post-Treatment

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1333 ◽  
Author(s):  
Woo Oh ◽  
Hyeon Lim ◽  
Jong Won ◽  
Seung Lee
Keyword(s):  
Crystalline Phase ◽  
Vinylidene Fluoride ◽  
Piezoelectric Properties ◽  
Testing Machine ◽  
Thermoplastic Composites ◽  
X Ray Diffraction ◽  
Universal Testing ◽  
Poly Vinylidene Fluoride ◽  
The Matrix ◽  
Poling Voltage

Thermoplastic composites were prepared using poly (vinylidene fluoride) (PVDF) as the matrix with piezoelectric properties and aromatic polyarylate (PAR) as the reinforcing component. The PVDF/PAR conjugate fibers were prepared by melt conjugate spinning. The PVDF/PAR composites were prepared by compression molding of the PVDF/PAR conjugate fiber laminates at various molding temperatures. Drawing and poling post-treatments of the PVDF/PAR composites were performed to increase the β crystalline phase content of the PVDF. The morphologies of the PVDF/PAR composites were observed by scanning electron microscopy, and the tensile properties were tested using an universal testing machine. The crystal structure of the PVDF/PAR composites was confirmed by Fourier transform infrared spectroscopy and X-ray diffraction. The piezoelectric properties were tested using voltmeters and multimeters. The post-treatments enhanced the content of the β crystalline phase of the PVDF matrix, thereby improving the piezoelectric properties of the composites. A molding temperature of 180 °C, drawing temperature of 90 °C, and poling voltage of 12 kV were identified as the optimal conditions for the preparation of the PVDF/PAR composite.

Simulations of High-Strain Electrostrictive Chlorinated Terpolymers

2003 ◽  
Vol 785 ◽  
Author(s):  
George J. Kavarnos ◽  
Thomas Ramotowski
Keyword(s):  
Vinylidene Fluoride ◽  
High Strain ◽  
Polymer Chains ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lamellar Structures ◽  
Annealing Conditions ◽  
Poly Vinylidene Fluoride ◽  
Electromechanical Responses ◽  
Kinetics Of

ABSTRACTChlorinated poly(vinylidene fluoride/trifluoroethylene) terpolymers are remarkable examples of high strain electrostrictive materials. These polymers are synthesized by copolymerizing vinylidene fluoride and trifluoroethylene with small levels of a third chlorinated monomer. The electromechanical responses of these materials are believed to originate from the chlorine atom, which, by its presence in the polymer chains and by virtue of its large van der Waals radius, destroys the long-range crystalline polar macro-domains and transforms the polymer from a normal to a high-strain relaxor ferroelectric. To exploit the strain properties of the terpolymer, it is desirable to understand the structural implications resulting from the presence of the chlorinated monomer. To this end, computations have been performed on model superlattices of terpolymers using quantum-mechanical based force fields. The focus has been on determining the energetics and kinetics of crystallization of the various polymorphs that have been identified by x-ray diffraction and fourier transform infrared spectroscopy. The chlorinated monomer is shown to act as a defect that can be incorporated into the lamellar structures of annealed terpolymer without a high cost in energy. The degree of incorporation of the chlorinated monomer into the crystal lattice is controlled by annealing conditions and ultimately determines the ferroelectric behavior of the terpolymers.

Development of self-poled PVDF/MWNT flexible nanocomposites with a boosted electroactive β-phase

2020 ◽  
Vol 44 (34) ◽  
pp. 14578-14591
Author(s):  
Akash M. Chandran ◽  
S. Varun ◽  
Prasanna Kumar S. Mural
Keyword(s):  
Vinylidene Fluoride ◽  
Piezoelectric Properties ◽  
Nanocomposite Films ◽  
Fabrication Method ◽  
Β Phase ◽  
Poly Vinylidene Fluoride ◽  
Dielectric And Piezoelectric Properties

In the present study, we report a simple fabrication method for poly(vinylidene fluoride) PVDF/MWCNT flexible nanocomposite films with a boosted electroactive phase that enhanced the dielectric and piezoelectric properties.

scholarly journals Effect of Cellulose Nanofibrils and TEMPO-mediated Oxidized Cellulose Nanofibrils on the Physical and Mechanical Properties of Poly(vinylidene fluoride)/Cellulose Nanofibril Composites

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1091 ◽  
Author(s):  
Eftihia Barnes ◽  
Jennifer A. Jefcoat ◽  
Erik M. Alberts ◽  
Mason A. McKechnie ◽  
Hannah R. Peel ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Vinylidene Fluoride ◽  
Cellulose Nanofibrils ◽  
Composite Films ◽  
Weight Ratio ◽  
Tensile Modulus ◽  
Physical And Mechanical Properties ◽  
Free Standing ◽  
Composite Surface ◽  
Poly Vinylidene Fluoride

Cellulose nanofibrils (CNFs) are high aspect ratio, natural nanomaterials with high mechanical strength-to-weight ratio and promising reinforcing dopants in polymer nanocomposites. In this study, we used CNFs and oxidized CNFs (TOCNFs), prepared by a 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation process, as reinforcing agents in poly(vinylidene fluoride) (PVDF). Using high-shear mixing and doctor blade casting, we prepared free-standing composite films loaded with up to 5 wt % cellulose nanofibrils. For our processing conditions, all CNF/PVDF and TOCNF/PVDF films remain in the same crystalline phase as neat PVDF. In the as-prepared composites, the addition of CNFs on average increases crystallinity, whereas TOCNFs reduces it. Further, addition of CNFs and TOCNFs influences properties such as surface wettability, as well as thermal and mechanical behaviors of the composites. When compared to neat PVDF, the thermal stability of the composites is reduced. With regards to bulk mechanical properties, addition of CNFs or TOCNFs, generally reduces the tensile properties of the composites. However, a small increase (~18%) in the tensile modulus was observed for the 1 wt % TOCNF/PVDF composite. Surface mechanical properties, obtained from nanoindentation, show that the composites have enhanced performance. For the 5 wt % CNF/PVDF composite, the reduced modulus and hardness increased by ~52% and ~22%, whereas for the 3 wt % TOCNF/PVDF sample, the increase was ~23% and ~25% respectively.

Clamping effect on the piezoelectric properties of poly(vinylidene fluoride-trifluoroethylene) copolymer

1993 ◽  
Vol 150 (1) ◽  
pp. 255-266 ◽  
Author(s):  
H. Wang ◽  
Q. M. Zhang ◽  
L. E. Cross ◽  
A. O. Sykes
Keyword(s):  
Vinylidene Fluoride ◽  
Piezoelectric Properties ◽  
Poly Vinylidene Fluoride

Surface Functionalization of a Poly(vinylidene fluoride): Effect on the Adhesive and Piezoelectric Properties

2009 ◽  
Vol 1 (12) ◽  
pp. 2902-2908 ◽  
Author(s):  
Ji Seok Lee ◽  
Gwang Ho Kim ◽  
Soon Man Hong ◽  
Hyoung Jin Choi ◽  
Yongsok Seo
Keyword(s):  
Surface Functionalization ◽  
Vinylidene Fluoride ◽  
Piezoelectric Properties ◽  
Poly Vinylidene Fluoride

Structures and Physical Properties of Multi-Walled Carbon Nanotube-Filled PVDF Thermoplastic Composites

2007 ◽  
Vol 124-126 ◽  
pp. 1117-1120 ◽  
Author(s):  
Dong Wook Chae ◽  
Young Wan Nam ◽  
Seung Sangh Wang ◽  
S.M. Hong
Keyword(s):  
Carbon Nanotube ◽  
Vinylidene Fluoride ◽  
Thermoplastic Composites ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Loading Level ◽  
Multi Walled Carbon Nanotube ◽  
Poly Vinylidene Fluoride ◽  
Internal Mixer

Poly(vinylidene fluoride) (PVDF) / multi-walled carbon nanotube (MWNT) thermoplastic composites was melt compounded in an internal mixer. The percolation level for this system in electrical conductivity clearly occured between 2 and 2.5 wt%. PVDF/MWNT thermoplastic composites exhibited an increased crystallization temperature with the loading level, at 10 wt% loading by ca. 6. In addition, they presented a shoulder posterior to the main melting peak and an increased endpoint of the peak. In the Wide Angle X-ray Diffraction (WAXD) patterns, the incorporation of MWNT produced a larger shoulder at 2θ =20.7° with increasing the loading level, corresponding to the β-form crystal of PVDF.

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