Effects of thermal treatment on phase transitions and on the mechanical relaxation in poly(vinylidene fluoride)

2003 ◽  
Author(s):  
N. Alves ◽  
C.X. Cardoso ◽  
A.E. Job ◽  
J.A. Giacometti
Keyword(s):  
Phase Transitions ◽  
Thermal Treatment ◽  
Vinylidene Fluoride ◽  
Mechanical Relaxation ◽  
Poly Vinylidene Fluoride

Theory of Structural Phase Transitions in Poly(Vinylidene Fluoride)

1979 ◽  
Vol 43 (6) ◽  
pp. 456-460 ◽  
Author(s):  
N. C. Banik ◽  
F. P. Boyle ◽  
T. J. Sluckin ◽  
P. L. Taylor ◽  
S. K. Tripathy ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Vinylidene Fluoride ◽  
Structural Phase ◽  
Structural Phase Transitions ◽  
Poly Vinylidene Fluoride

scholarly journals Chemical and Morphological Transition of Poly(acrylonitrile)/Poly(vinylidene Fluoride) Blend Nanofibers during Oxidative Stabilization and Incipient Carbonization

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1210 ◽  
Author(s):  
Martin Wortmann ◽  
Natalie Frese ◽  
Al Mamun ◽  
Marah Trabelsi ◽  
Waldemar Keil ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Vinylidene Fluoride ◽  
Morphological Changes ◽  
Thermal Characterization ◽  
Morphological Transition ◽  
Oxidative Stabilization ◽  
Characterization Methods ◽  
Binary Polymer ◽  
Poly Vinylidene Fluoride ◽  
Poly Acrylonitrile

Thermally stabilized and subsequently carbonized nanofibers are a promising material for many technical applications in fields such as tissue engineering or energy storage. They can be obtained from a variety of different polymer precursors via electrospinning. While some methods have been tested for post-carbonization doping of nanofibers with the desired ingredients, very little is known about carbonization of blend nanofibers from two or more polymeric precursors. In this paper, we report on the preparation, thermal treatment and resulting properties of poly(acrylonitrile) (PAN)/poly(vinylidene fluoride) (PVDF) blend nanofibers produced by wire-based electrospinning of binary polymer solutions. Using a wide variety of spectroscopic, microscopic and thermal characterization methods, the chemical and morphological transition during oxidative stabilization (280 °C) and incipient carbonization (500 °C) was thoroughly investigated. Both PAN and PVDF precursor polymers were detected and analyzed qualitatively and quantitatively during all stages of thermal treatment. Compared to pure PAN nanofibers, the blend nanofibers showed increased fiber diameters, strong reduction of undesired morphological changes during oxidative stabilization and increased conductivity after carbonization.

Effect of Thermal Treatment on the Physical Properties of Electrospun PVDF Membrane

2012 ◽  
Vol 591-593 ◽  
pp. 1113-1116
Author(s):  
Si Chen Cheng ◽  
Yin Zheng Liang ◽  
Yi Ping Qiu
Keyword(s):  
Thermal Treatment ◽  
Tensile Property ◽  
Tensile Testing ◽  
Vinylidene Fluoride ◽  
X Ray Diffraction ◽  
Electrospinning Technique ◽  
Pvdf Membrane ◽  
X Ray ◽  
Before And After ◽  
Poly Vinylidene Fluoride

The electrospinning technique was used to produce poly (vinylidene fluoride) (PVDF) membrane. Thermal treatment was introduced to improve the mechanical property and dimensional stability. In this paper, the PVDF membranes before and after thermal treatment were characterized by Scanning electron microscope (SEM), differential scanning calorimeter (DSC) and wide angle X-ray diffraction (WAXD), tensile testing. The crystallinity, tensile property, as well as melting temperature changed with the treated temperature. The results hows that thermal treatment could notably increase the tensile property of electrospun PVDF membrane and 160°C is a proper temperature for thermal treating

The Microstructural, Mechanical and Electro-Mechanical Properties of Graphene Aerogel-PVDF Nanoporous Composites

2014 ◽  
Vol 29 ◽  
pp. 1-6 ◽  
Author(s):  
Guang Ping Zheng ◽  
Z. Han ◽  
Y.Z. Liu
Keyword(s):  
Electrical Resistance ◽  
High Performance ◽  
Vinylidene Fluoride ◽  
Mechanical Relaxation ◽  
Graphene Aerogel ◽  
Energy Harvesters ◽  
Poly Vinylidene Fluoride ◽  
Mechanical Behaviours ◽  
Stress Dependent ◽  
Hybrid Scaffolds

Graphene aerogel-poly (vinylidene fluoride) (GA-PVDF) nanoporous composites with different concentrations of PVDF are fabricated. Scanning electron microscopy reveals that PVDF films with a typical thickness below 100 nm are coated at the graphene sheets in the nanoporous composites. The GA-PVDF composites show excellent compressibility, ductility and mechanical strength, as well as better sensitivity of stress-dependent electrical resistance compared with those of GAs. The improved mechanical and electro-mechanical behaviours of nanoporous composites are ascribed to the PVDF which possesses piezoelectricity. The structural properties of the graphene-PVDF nanosized hybrid scaffolds are analyzed by dynamical mechanical relaxation. The results demonstrate that the nanoporous composites could be used as high-performance sensors, actuators and kinetic energy harvesters.

Effect of Thermal Treatment on the Physical Properties of Electrospun PVDF/PMMA Composite Membrane

2013 ◽  
Vol 750-752 ◽  
pp. 224-227
Author(s):  
Jian Meng Zhao ◽  
Yin Zheng Liang ◽  
Si Chen Cheng ◽  
Yi Ping Qiu
Keyword(s):  
Thermal Treatment ◽  
Pore Size ◽  
Tensile Property ◽  
Composite Membrane ◽  
Vinylidene Fluoride ◽  
Electrospinning Technique ◽  
Electrolyte Uptake ◽  
Before And After ◽  
Poly Vinylidene Fluoride ◽  
Uptake Test

Poly (vinylidene fluoride) (PVDF) / poly(methyl methacrylate) (PMMA) composite membrane was produced by the electrospinning technique. Thermal treatment was introduced to improve the mechanical property and dimensional stability. In this paper, the PVDF/PMMA membranes before and after thermal treatment were characterized by Scanning electron microscope (SEM), differential scanning calorimeter (DSC) , pore size and porosity test, electrolyte uptake test and tensile test. The pore size, porosity, electrolyte uptake rate, tensile property, as well as melting temperature and crystallinity changed with the treated temperature. The results show that thermal treatment could notably increase the tensile property of electrospun PVDF/PMMA composite membrane and 160°C is a proper temperature for thermal treating.

The role of molecular defects on the structure and phase transitions of poly(vinylidene fluoride)

Polymer ◽  
1987 ◽  
Vol 28 (4) ◽  
pp. 617-626 ◽  
Author(s):  
Andrew J. Lovinger ◽  
D.D. Davis ◽  
R.E. Cais ◽  
J.M. Kometani
Keyword(s):  
Phase Transitions ◽  
Vinylidene Fluoride ◽  
Molecular Defects ◽  
Poly Vinylidene Fluoride

Crystalline phase of inorganic montmorillonite/poly(vinylidene fluoride) nanocomposites: influence of dispersion of nanolayers

2017 ◽  
Vol 37 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Chao Fu ◽  
Xuemei Wang ◽  
Xiang Shi ◽  
Xianghai Ran
Keyword(s):  
Thermal Treatment ◽  
Crystalline Phase ◽  
Crystallization Process ◽  
Vinylidene Fluoride ◽  
Polar Phase ◽  
Solution Casting ◽  
Casting Method ◽  
Poly Vinylidene Fluoride ◽  
Solution Casting Method ◽  
Co Precipitation

Abstract Inorganic montmorillonite (MMT)/poly(vinylidene fluoride) nanocomposites were prepared by two methods: co-precipitation and solution casting. The effect of preparation methods and thermal treatment on crystalline phase was investigated by Fourier transform infrared spectroscopy and differential scanning calorimetry tests. The isothermal crystallization process was observed with polarized optical microscopy. It was found that the solution-casting method was more effective than the co-precipitation method in inducing the polar phase in the melt-isothermal crystallization process. The addition of inorganic MMT by the solution-casting method without further thermal treatment promoted the β-phase crystallization. The inorganic MMT significantly improved the γ phase of the solution-cast samples in the melt-recrystallization process. The degree of dispersion of inorganic MMT influenced the relative content of the polar phase and the crystallinity of the samples in the same crystallization conditions, i.e. the preparation method and the thermal treatment. The effect of dispersion on crystallization kinetics was also studied to verify the enhancement of finely dispersed nanolayer clusters on the γ phase.

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