scholarly journals Influence of thermal treatment on the properties and intermolecular interactions of epoxidized natural rubber-salt systems

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nurul Fatahah Asyqin Zainal ◽  
Hairunnisa Ramli ◽  
Margarethe Fritz ◽  
Volker Abetz ◽  
Chin Han Chan
Keyword(s):  
Thermal Treatment ◽  
Natural Rubber ◽  
Intermolecular Interactions ◽  
Polymer Electrolytes ◽  
Salt Content ◽  
Ionic Conductivities ◽  
Solid Polymer Electrolytes ◽  
Epoxidized Natural Rubber ◽  
Solid Polymer ◽  
Salt Systems

Abstract The influence of thermal treatment on the thermal stability, thermal properties, dielectric properties and intermolecular interaction of binary epoxidized natural rubber (ENR)-salt systems, which may be a candidate for solid polymer electrolytes (SPEs) was investigated. Solubility of salt in ENR enhances, which may be due to the disruption of the lightly-crosslinked microgel under heat treatment. The increase in the ionic conductivities of the thermally treated ENR SPEs at constant salt content is correlated to the higher glass transition temperatures, development of percolation network and higher extent of intermolecular interactions between ENR and charged entities in this study.

Solid Polymer Electrolytes from Crosslinked PEG and Dilithium N,N'-Bis(trifluoromethanesulfonyl)perfluoroalkane-1,ω-disulfonamide and Lithium Bis(trifluoromethanesulfonyl)imide Salts

2008 ◽  
Vol 73 (12) ◽  
pp. 1777-1798 ◽  
Author(s):  
Olt E. Geiculescu ◽  
Rama V. Rajagopal ◽  
Emilia C. Mladin ◽  
Stephen E. Creager ◽  
Darryl D. Desmarteau
Keyword(s):  
Ionic Conductivity ◽  
Polymer Electrolytes ◽  
Minimum Energy ◽  
Ionic Conductivities ◽  
Solid Polymer Electrolytes ◽  
Solid Polymer ◽  
Segmental Motion ◽  
Concentrated Electrolytes ◽  
Two Factors ◽  
Poly Ethylene

The present work consists of a series of studies with regard to the structure and charge transport in solid polymer electrolytes (SPE) prepared using various new bis(trifluoromethanesulfonyl)imide (TFSI)-based dianionic dilithium salts in crosslinked low-molecular-weight poly(ethylene glycol). Some of the thermal properties (glass transition temperature, differential molar heat capacity) and ionic conductivities were determined for both diluted (EO/Li = 30:1) and concentrated (EO/Li = 10:1) SPEs. Trends in ionic conductivity of the new SPEs with respect to anion structure revealed that while for the dilute electrolytes ionic conductivity is generally rising with increased length of the perfluoroalkylene linking group in the dianions, for the concentrated electrolytes the trend is reversed with respect to dianion length. This behavior could be the result of a combination of two factors: on one hand a decrease in dianion basicity that results in diminished ion pairing and an enhancement in the number of charge carriers with increasing fluorine anion content, thereby increasing ionic conductivity while on the other hand the increasing anion size and concentration produce an increase in the friction/entanglements of the polymeric segments which lowers even more the reduced segmental motion of the crosslinked polymer and decrease the dianion contribution to the overall ionic conductivity. DFT modeling of the same TFSI-based dianionic dilithium salts reveals that the reason for the trend observed is due to the variation in ion dissociation enthalpy, derived from minimum-energy structures, with respect to perfluoroalkylene chain length.

scholarly journals Low Frequency Dielectric Relaxation and Conductance of Solid Polymer Electrolytes with PEO and Blends of PEO and PMMA

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1009 ◽  
Author(s):  
Chin Han Chan ◽  
Hans-Werner Kammer
Keyword(s):  
Polymer Electrolytes ◽  
Room Temperature ◽  
Glassy State ◽  
Salt Content ◽  
Complex Impedance ◽  
Low Frequency ◽  
Solid Polymer Electrolytes ◽  
Solid Polymer ◽  
Tangent Loss ◽  
Conductivity Mechanism

Solid polymer electrolytes are mixtures of polymer and inorganic salt. There are quite a number of studies dealing with the relationship between electric conductivity and structural relaxation in solid polymer electrolytes. We present a phenomenological approach based on fluctuation-dissipation processes. Phase heterogeneity appears in poly(ethylene oxide) (PEO) of high molecular mass and its blends due to crystallization and accompanying phase segregation. Addition of salt hampers crystallization, causing dynamic heterogeneity of the salt mixtures. Conductivity is bound to amorphous phase; the conductivity mechanism does not depend on content of added salt. One observes dispersion of conductivity relaxation only at low frequency. This is also true for blends with poly(methyl methacrylate) (PMMA). In blends, the dynamics of relaxation depend on glass transition of the system. Glassy PMMA hampers relaxation at room temperature. Relaxation can only be observed when salt content is sufficiently high. As long as blends are in rubbery state at room temperature, they behave PEO-like. Blends turn into glassy state when PMMA is in excess. Decoupling of long-ranging and dielectric short-ranging relaxation can be observed. Conductivity mechanism in PEO, as well as in blends with PMMA were analyzed in terms of complex impedance Z*, complex permittivity, tangent loss spectra and complex conductivity.

Studies on thin films of PVC-PMMA blend polymer electrolytes

2013 ◽  
Vol 33 (7) ◽  
pp. 633-638 ◽  
Author(s):  
Mohammad Saleem Khan ◽  
Rahmat Gul ◽  
Mian Sayed Wahid
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Ionic Conductivity ◽  
Polymer Electrolyte ◽  
Polymer Electrolytes ◽  
Ethylene Carbonate ◽  
Salt Content ◽  
Solid Polymer Electrolytes ◽  
Solid Polymer ◽  
Degree Of Crystallinity

Abstract Thin films of poly (vinyl chloride) (PVC)/poly (methyl methacrylate) (PMMA) blend polymers complexed with different concentrations of LiClO4 salt, containing ethylene carbonate (EC) as the plasticizer, were fabricated by the solution cast procedure. Ionic conductivity, thermal stability and X-ray diffraction (XRD) studies were undertaken. AC impedance measurements were done in the temperature range of 20–70°C. The highest ionic conductivity at room temperature was found to be 2.23×10-5 S cm-1 for the sample containing 15 wt% of LiClO4 salt. The XRD technique was used to investigate the structure and complex formation of solid polymer electrolytes. There was a decrease in degree of crystallinity. The amorphous nature of complexed solid polymer blend electrolyte films increased, due to the addition of LiClO4 salt. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) revealed the effect of salt on the thermal stability of the polymer electrolytes. It was found that these polymer electrolyte systems show stability up to about 280°C. It was also found that, with increased LiClO4 salt content in complexed polymer electrolyte systems, the degradation temperature decreased.

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