Influence of Crystallization Condition on Structure of P(VDF-CTFE) Copolymers

2005 ◽  
Vol 889 ◽  
Author(s):  
Xin Yang ◽  
Zhimin Li ◽  
LeVar Odum ◽  
Z.-Y. Cheng
Keyword(s):  
Crystallization Temperature ◽  
Vinylidene Fluoride ◽  
Crystallization Condition ◽  
Unstable Phase ◽  
Poly Vinylidene Fluoride ◽  
Influence Of Crystallization

ABSTRACTThe influence of the crystallization condition - temperature and time - on the structure of poly (vinylidene fluoride chlorotrifluoroethylene), P(VDF-CTFE), was studied using DSC and XRD. The DSC results of all studied polymers show three peaks. One peak, which is associated with crystallization temperature, represents the appearance of unstable phase in the polymers. Both XRD and DSC data indicate the coexistence of different phases in the polymers, which may be the reason for the high electrostrictive performance obtained in the polymers.

Crystallization Behaviours of Poly(vinylidene fluoride) (PVDF) Nanocomposites with MoS2 Nanosheets with Different Surface Functional Groups

2020 ◽  
Vol 20 (12) ◽  
pp. 7535-7543
Author(s):  
Guihai Gan ◽  
Cheng Wang ◽  
Pengpeng Chen ◽  
Jichang Liu
Keyword(s):  
Thermal Stability ◽  
Crystallization Temperature ◽  
Vinylidene Fluoride ◽  
Crystallization Rate ◽  
Cold Crystallization ◽  
Degree Of Crystallinity ◽  
Mos2 Nanosheets ◽  
Surface Functional Groups ◽  
Poly Vinylidene Fluoride ◽  
Thermal Stability Of

The crystallization behaviours of amorphous poly(vinylidene fluoride) (PVDF) nanocompositesmodified with two different kinds of molybdenum disulfide (MoS2) at different filler loadings were investigated in detail in this work. The crystallinity, melting temperature and crystallization temperature of the PVDF/MoS2 nanocomposites were transformed from α-phase to β-phase with the addition of MoS2, MoS2-COOH and MoS2-NH2. During isothermal cold crystallization, the overall crystallization rate of PVDF was slowed with increased MoS2 loading relative to that of neat PVDF. Moreover, the crystallization temperature of the PVDF nanocomposites increased with the addition of MoS2 despite the cooling rate during nonisothermal cold crystallization. DMA tests showed that the storage modulus of PVDF was decreased with the addition of MoS2, while those of PVDF/MoS2-COOH and PVDF/MoS2-NH2 were enhanced to different degrees. The decomposition of the PVDF/MoS2 nanocomposites were also discussed. Relative to neat PVDF, the thermal stability of PVDF was obviously improved with the addition of MoS2, MoS2-COOH and MoS2-NH2, which could be ascribed to the increased degree of crystallinity.

Effect of High-Energy-Electron Irradiation on Nonisothermal Crystallization Kinetics in P(VDF-TrFE) 65/35 mol% Copolymers

2005 ◽  
Vol 889 ◽  
Author(s):  
Zhi-Min Li ◽  
Z.-Y. Cheng
Keyword(s):  
Electron Irradiation ◽  
Crystallization Temperature ◽  
Vinylidene Fluoride ◽  
High Energy ◽  
Energy Electron ◽  
Three Dimensions ◽  
High Energy Electron ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Poly Vinylidene Fluoride

ABSTRACTThe effect of the high-energy-electron irradiation on the crystallization process in poly(vinylidene fluoride-trifluoroethyelene) [(P(VDF-TrFE)] 65/35 mol% copolymers was studied by nonisothermal crystallization using the differential scanning calorimetry (DSC) technique. The experimental data are analyzed using modified Avrami, Ozawa, and combined Avrami-Ozawa methods. It is found that the crystals grow in three dimensions in the irradiated samples. It is found that the irradiation results in a lower crystallization temperature and a lower crystallization activation energy. It is also found that the irradiated samples have a lower crystallization temperature than the unirradiated samples. All these results indicate that the crystals grown in the irradiated samples have a smaller surface energy, which corresponds to a thicker interfacial layer.

Piezoelectric β-polymorph formation of new textiles by surface modification with coating process based on interfacial interaction on the conformational variation of poly (vinylidene fluoride) (PVDF) chains

2020 ◽  
Vol 91 (3) ◽  
pp. 31301
Author(s):  
Nabil Chakhchaoui ◽  
Rida Farhan ◽  
Meriem Boutaldat ◽  
Marwane Rouway ◽  
Adil Eddiai ◽  
...  
Keyword(s):  
High Efficiency ◽  
Vinylidene Fluoride ◽  
Research Work ◽  
Research Area ◽  
Interfacial Interaction ◽  
Tetraethyl Orthosilicate ◽  
Poly Vinylidene Fluoride ◽  
Carbon Nanofillers ◽  
The Impact ◽  
Advanced Applications

Novel textiles have received a lot of attention from researchers in the last decade due to some of their unique features. The introduction of intelligent materials into textile structures offers an opportunity to develop multifunctional textiles, such as sensing, reacting, conducting electricity and performing energy conversion operations. In this research work nanocomposite-based highly piezoelectric and electroactive β-phase new textile has been developed using the pad-dry-cure method. The deposition of poly (vinylidene fluoride) (PVDF) − carbon nanofillers (CNF) − tetraethyl orthosilicate (TEOS), Si(OCH2CH3)4 was acquired on a treated textile substrate using coating technique followed by evaporation to transform the passive (non-functional) textile into a dynamic textile with an enhanced piezoelectric β-phase. The aim of the study is the investigation of the impact the coating of textile via piezoelectric nanocomposites based PVDF-CNF (by optimizing piezoelectric crystalline phase). The chemical composition of CT/PVDF-CNC-TEOS textile was detected by qualitative elemental analysis (SEM/EDX). The added of 0.5% of CNF during the process provides material textiles with a piezoelectric β-phase of up to 50% has been measured by FTIR experiments. These results indicated that CNF has high efficiency in transforming the phase α introduced in the unloaded PVDF, to the β-phase in the case of nanocomposites. Consequently, this fabricated new textile exhibits glorious piezoelectric β-phase even with relatively low coating content of PVDF-CNF-TEOS. The study demonstrates that the pad-dry-cure method can potentially be used for the development of piezoelectric nanocomposite-coated wearable new textiles for sensors and energy harvesting applications. We believe that our study may inspire the research area for future advanced applications.

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