The dependence of the β-to-α phase transition behavior of poly(1,4-butylene adipate) on phase separated morphology in its blends with poly(vinylidene fluoride)

2018 ◽  
Vol 20 (23) ◽  
pp. 15718-15724 ◽  
Author(s):  
Chunyue Hou ◽  
Huihui Li ◽  
Xiaoli Sun ◽  
Shouke Yan ◽  
Yanfang Wang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Vinylidene Fluoride ◽  
Phase Transition Behavior ◽  
Transition Behavior ◽  
Α Phase ◽  
Poly Vinylidene Fluoride ◽  
The Stability

Two kinds of typical phase separated morphologies are prepared and they alter the stability of crystals.

Phase transition behavior of Poly(vinylidene fluoride) in a blend with Poly(butylene adipate) at high temperature

Polymer ◽  
2020 ◽  
Vol 194 ◽  
pp. 122409
Author(s):  
Zihan Tang ◽  
Sihan Yang ◽  
Haijun Wang ◽  
Xiaoli Sun ◽  
Zhongjie Ren ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Vinylidene Fluoride ◽  
Phase Transition Behavior ◽  
Transition Behavior ◽  
Poly Vinylidene Fluoride

Stretching Induced Crystalline-Phase Transition in Energy-Conversion Poly(Vinylidene Fluoride) (PVDF) Films

2014 ◽  
Vol 1070-1072 ◽  
pp. 589-593
Author(s):  
Fei Peng Wang ◽  
Zheng Yong Huang ◽  
Jian Li
Keyword(s):  
Phase Transition ◽  
Crystalline Phase ◽  
High Speed ◽  
Vinylidene Fluoride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Α Phase ◽  
Poly Vinylidene Fluoride ◽  
Crystalline Phase Transition

Commercial poly (vinylidene fluoride) (PVDF) films are uniaxially stretched with varying rates at 110 °C in order to endow PVDF piezo-and pyroelectric by crystalline-phase transition from α to β during the stretching. The crystalline phases are determined by infrared spectroscopy. The β-phase content and its fraction in films increase as a result of stretching with high rates. In addition, higher stretching rates yield a slight increase of γ phase. The crystallite size is evaluated by means of X-ray diffraction. It is found that the β-phase crystallites become smaller with fast stretching, whereas the α-phase crystallites are cracked and disappear at high-speed stretching of 2.5 /min.

Phase Transition in Poly(Vinylidene Fluoride) Investigated with Micro-Raman Spectroscopy

2005 ◽  
Vol 59 (3) ◽  
pp. 275-279 ◽  
Author(s):  
C. J. L. Constantino ◽  
A. E. Job ◽  
R. D. Simões ◽  
J. A. Giacometti ◽  
V. Zucolotto ◽  
...  
Keyword(s):  
Phase Transition ◽  
Raman Spectroscopy ◽  
Vinylidene Fluoride ◽  
Raman Band ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Β Phase ◽  
Α Phase ◽  
Poly Vinylidene Fluoride

The phase transition from the non-polar α-phase to the polar β-phase of poly(vinylidene fluoride) (PVDF) has been investigated using micro-Raman spectroscopy, which is advantageous because it is a nondestructive technique. Films of α-PVDF were subjected to stretching under controlled rates at 80 °C, while the transition to β-PVDF was monitored by the decrease in the Raman band at 794 cm−1 characteristic of the α-phase, along with the concomitant increase in the 839 cm−1 band characteristic of the β-phase. The α→β transition in our PVDF samples could be achieved even for the sample stretched to twice (2×-stretched) the initial length and it did not depend on the stretching rate in the range between 2.0 and 7.0 mm/min. These conclusions were corroborated by differential scanning calorimetry (DSC) and X-ray diffraction experiments for PVDF samples processed under the same conditions as in the Raman scattering measurements. Poling with negative corona discharge was found to affect the α-PVDF morphology, improving the Raman bands related to this crystalline phase. This effect is minimized for films stretched to higher ratios. Significantly, corona-induced effects could not be observed with the other experimental techniques, i.e., X-ray diffraction and infrared spectroscopy.

Sign in / Sign up

Export Citation Format

Share Document