Crystallization of poly(vinylidene fluoride): Equilibrium melting point and heat of fusion of the α-polymorph

1976 ◽  
Vol 14 (9) ◽  
pp. 1683-1692 ◽  
Author(s):  
Gordon J. Welch ◽  
Robert L. Miller
Keyword(s):  
Melting Point ◽  
Vinylidene Fluoride ◽  
Heat Of Fusion ◽  
Equilibrium Melting Point ◽  
Poly Vinylidene Fluoride

CaCu3Ti4O12–PVDF polymeric composites with enhanced capacitive energy density

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540003 ◽  
Author(s):  
Xin Ouyang ◽  
Peng Cao ◽  
Weijun Zhang ◽  
Zhuofeng Liu ◽  
Zhaohui Huang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Melting Point ◽  
Energy Density ◽  
Vinylidene Fluoride ◽  
Dielectric Breakdown ◽  
Melt Blending ◽  
Capacitive Energy Storage ◽  
Poly Vinylidene Fluoride

CaCu 3 Ti 4 O 12 (CCTO)–poly(vinylidene fluoride (PVDF)) composites were prepared by melt blending and hot molding techniques. The addition of CCTO remarkably enhanced the dielectric properties and the thermal conductivity of PVDF composites, while the melting point of the PVDF composites (~170°C) was almost independent of the CCTO concentration. Based on the results of dielectric constant and dielectric breakdown voltage, the PVDF composite containing 40 vol.% CCTO fillers shows the optimized capacitive energy storage potential (7.81 J/cm3).

Melt Crystallization of Nanocomposites of Poly(Vinylidene Fluoride) with OMS

2006 ◽  
Vol 949 ◽  
Author(s):  
Bedriye Seyhan Ince-Gunduz ◽  
Debeshu Amare ◽  
Robert Alpern ◽  
Peggy Cebe ◽  
Jennifer Crawford ◽  
...  
Keyword(s):  
Growth Rate ◽  
Melting Point ◽  
Optical Microscopy ◽  
Vinylidene Fluoride ◽  
Crystallinity Index ◽  
Beta Phase ◽  
Alpha Phase ◽  
Melt Crystallization ◽  
Poly Vinylidene Fluoride ◽  
The Impact

ABSTRACTIn our previous work [1] we investigated the impact of cold-crystallization on the structure of nanocomposites of PVDF with Lucentite STN™ OMS and observed the crossover composition in which the crystallographic beta phase dominated over alpha phase. Here, melt crystallization of PVDF/OMS nanocomposites was studied in the range of 0 to 1.0 wt% of OMS. In crystallization from melt, a decrease in crystallinity index occurs as a result of an increase in OMS. While beta phase fraction increased with an increase of OMS content in the range of interest, the amount of alpha crystals was found to be dominant even at high OMS compositions. At 1.0 wt% of OMS, beta crystals had reached at most 30% of the total crystallinity. Polarizing optical microscopy (POM) studies showed smaller, less birefringent spherulites with higher melting temperature compared to alpha spherulites appeared with OMS addition. Growth rate of these weakly birefringent spherulites is smaller than that of the strongly birefringent alpha spherulites. The increase in size and amount of the weakly birefringent spherulites with an increase of OMS and their higher melting point suggests these spherulites may be in the beta crystallographic phase.

scholarly journals Effect of Annealing Temperature on the Morphology and Piezoresponse Characterisation of Poly(vinylidene fluoride-trifluoroethylene) Films via Scanning Probe Microscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
K. Lau ◽  
Y. Liu ◽  
H. Chen ◽  
R. L. Withers
Keyword(s):  
Melting Point ◽  
Annealing Temperature ◽  
Vinylidene Fluoride ◽  
Hysteresis Loops ◽  
Piezoresponse Force Microscopy ◽  
Scanning Probe ◽  
Force Microscopy ◽  
Poly Vinylidene Fluoride ◽  
Probe Microscope ◽  
Small Grains

Poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE (70/30)) films were synthesized on a gold/glass substrate via spin coating. The films were annealed at a temperature between125∘Cand180∘C. Nanoscale characterisation of the morphology, polarization switching, and local piezoresponse hysteresis loops of PVDF-TrFE film was studied using a scanning probe microscope (SPM). Ferroelectric switchable domains were identified by piezoresponse force microscopy (PFM) for all films. Small grains, with weak piezoresponse character, were observed for films annealed just above the Curie temperature. Acicular grains were obtained when the annealing temperature approached the melting point and the piezoresponse increased. Annealing above the melting point decreased the piezoresponse and the morphology changed dramatically into plate-like structures.

Crystallographic features of poly(vinylidene fluoride) film upon an attractive substrate of KBr

2017 ◽  
Vol 19 (40) ◽  
pp. 27828-27838 ◽  
Author(s):  
Rui Huang ◽  
Gang Wang ◽  
Shuo Guo ◽  
Ke Wang ◽  
Qiang Fu
Keyword(s):  
Melting Point ◽  
Vinylidene Fluoride ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Poly Vinylidene Fluoride ◽  
Electrical Breakdown Strength ◽  
Irradiation Resistance

Among all the polymorphs of poly(vinylidene fluoride) (PVDF), the polar γ-form possesses the highest melting point and electrical breakdown strength as well as the strongest solvent and irradiation resistance, which are beneficial for the durability of PVDF products.

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