scholarly journals Multiple-Step Melting/Irradiation: A Strategy to Fabricate Thermoplastic Polymers with Improved Mechanical Performance

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1812
Author(s):  
Jingxin Zhao ◽  
Jiayao Wang ◽  
Xiaojun Ding ◽  
Yu Gu ◽  
Yongjin Li ◽  
...  

To fabricate thermoplastic polymers exhibiting improved ductility without the loss of strength, a novel multiple-step melting/irradiation (MUSMI) strategy was developed by taking poly(vinylidene fluoride)/triallyl isocyanate (PVDF/TAIC) as an example, in which alternate melting and irradiation were adopted and repeated for several times. The initial irradiation with a low dose produced some local crosslinked points (not 3-dimensional network). When the specimen was reheated above the melting temperature, they redistributed in the PVDF matrix, which is an efficient way to avoid the high crosslinking density at certain positions and the disappearance of thermoplastic properties. During the subsequent cooling process, the crosslinked domains in the thermoplastic polymer matrix is expected to play double roles in turning crystal structures for enhancing the ductility without reducing strength. On one hand, they can act as heterogeneous nucleation agents, resulting in higher nucleation density and smaller spherulites; on the other hand, the existence of crosslinked structures restricts the lamellar thickening, accounting for the thinner crystal lamellae. Both smaller spherulites and thinner lamellae contribute to better ductility. At the same time, these local crosslinked points enhance the connectivity of crystal structures (including lamellae and spherulites), which is beneficial to the improvement of strength. Based on the influence of local crosslinked points on the ductility and strength, thermoplastic PVDF with much higher elongation at break and comparable yielding stress (relative to the reference specimen upon strong irradiation only once) was prepared via MUSMI successfully.

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4284
Author(s):  
María Fernanda Bósquez-Cáceres ◽  
Sandra Hidalgo-Bonilla ◽  
Vivian Morera Córdova ◽  
Rose M. Michell ◽  
Juan P. Tafur

The diversification of current forms of energy storage and the reduction of fossil fuel consumption are issues of high importance for reducing environmental pollution. Zinc and magnesium are multivalent ions suitable for the development of environmentally friendly rechargeable batteries. Nanocomposite polymer electrolytes (NCPEs) are currently being researched as part of electrochemical devices because of the advantages of dispersed fillers. This article aims to review and compile the trends of different types of the latest NCPEs. It briefly summarizes the desirable properties the electrolytes should possess to be considered for later uses. The first section is devoted to NCPEs composed of poly(vinylidene Fluoride-co-Hexafluoropropylene). The second section centers its attention on discussing the electrolytes composed of poly(ethylene oxide). The third section reviews the studies of NCPEs based on different synthetic polymers. The fourth section discusses the results of electrolytes based on biopolymers. The addition of nanofillers improves both the mechanical performance and the ionic conductivity; key points to be explored in the production of batteries. These results set an essential path for upcoming studies in the field. These attempts need to be further developed to get practical applications for industry in large-scale polymer-based electrolyte batteries.


2009 ◽  
Vol 27 (04) ◽  
pp. 511 ◽  
Author(s):  
Yi Lin ◽  
Yong-yi Yao ◽  
Xiao-zhan Yang ◽  
Li-ming Shen ◽  
Rui-xia Li ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 743
Author(s):  
Erlantz Lizundia ◽  
Ander Reizabal ◽  
Carlos M. Costa ◽  
Alberto Maceiras ◽  
Senentxu Lanceros-Méndez

Cellulose nanocrystals (CNCs) were incorporated into poly (vinylidene fluoride) (PVDF) to tailor the mechanical and dielectric properties of this electroactive polymer. PVDF/CNC nanocomposites with concentrations up to 15 wt.% were prepared by solvent-casting followed by quick vacuum drying in order to ensure the formation of the electroactive γ-phase. The changes induced by the presence of CNCs on the morphology of PVDF and its crystalline structure, thermal properties, mechanical performance and dielectric behavior are explored. The results suggest a relevant role of the CNC surface −OH groups, which interact with PVDF fluorine atoms. The real dielectric constant ε’ of nanocomposites at 200 Hz was found to increase by 3.6 times up to 47 for the 15 wt.% CNC nanocomposite due to an enhanced ionic conductivity provided by CNCs. The approach reported here in order to boost the formation of the γ-phase of PVDF upon the incorporation of CNCs serves to further develop cellulose-based multifunctional materials.


2019 ◽  
Vol 10 (11) ◽  
pp. 1335-1343 ◽  
Author(s):  
Niels L. Meereboer ◽  
Ivan Terzić ◽  
Katja Loos

Crosslinking poly(VDF-co-VA) copolymers leads to a change from ferroelectric to double hysteresis loop behavior when the crosslinking density is increased.


1972 ◽  
Vol 3 (5) ◽  
pp. 600-610 ◽  
Author(s):  
Ryozo Hasegawa ◽  
Yasuhiro Takahashi ◽  
Yozo Chatani ◽  
Hiroyuki Tadokoro

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