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Electrophysical behavior of ion-conductive organic-inorganic polymer system based on aliphatic epoxy resin and salt of lithium perchlorate.

Matkovska L, Iurzhenko M, Mamunya Y, Matkovska O, Demchenko V, Lebedev E, Boiteux G, Serghei A - Nanoscale Res Lett (2014)

Bottom Line: The effect of LiClO4 content on the electrophysical properties of epoxy polymers has been studied by differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS).The effect of LiClO4 content on the structure has been studied by wide-angle X-ray scattering (WAXS).The presence of ether oxygen in DEG macromolecules provides a transfer mechanism of the lithium cations with the ether oxygen similar to polyethylene oxide (PEO).

View Article: PubMed Central - PubMed

Affiliation: Institute of Macromolecular Chemistry of National Academy of Sciences of Ukraine, Kyiv, 02160, Ukraine, LOVEMK@ukr.net.

ABSTRACT

Unlabelled: In the present work, ion-conductive hybrid organic-inorganic polymers based on epoxy oligomer of diglycide aliphatic ester of polyethylene glycol (DEG) and lithium perchlorate (LiClO4) were synthesized. The effect of LiClO4 content on the electrophysical properties of epoxy polymers has been studied by differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS). The effect of LiClO4 content on the structure has been studied by wide-angle X-ray scattering (WAXS). It was found that LiClO4 impacts on the structure of the synthesized hybrid epoxy polymers, probably, by formation of coordinative complexes {ether oxygen-lithium cations-ether oxygen} as evidenced from a significant increase in their glass transition temperatures with increasing LiClO4 concentration and WAXS studies. The presence of ether oxygen in DEG macromolecules provides a transfer mechanism of the lithium cations with the ether oxygen similar to polyethylene oxide (PEO). Thus, the obtained hybrid polymers have high values of ionic conductivity σ' (approximately 10(-3) S/cm) and permittivity ϵ' (6 × 10(5)) at elevated temperatures (200°С). On the other hand, DEG has higher heat resistance compared to PEO that makes these systems perspective as solid polymer electrolytes able to operate at high temperature.

Pacs: 81.07.Pr; 62.23.St; 66.30.hk.

No MeSH data available.


Related in: MedlinePlus

Scheme of lithium cation transfer in the DEG/LiClO4system. The lithium cation transfer along the DEG polymer chain.
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Fig4: Scheme of lithium cation transfer in the DEG/LiClO4system. The lithium cation transfer along the DEG polymer chain.

Mentions: Figure 3 shows the isothermal spectra of the real part of the complex permittivity (ϵ') and the conductivity (σ') for different concentrations of LiClO4 in DEG obtained in the temperature range from −60°C to 200°C. One can see that values and character of the σ' and ϵ' curves depend on two factors: the content of LiClO4 and the temperature of measurements. At temperatures below the glass transition, the permittivity has low values and hardly varies with frequency indicating the ‘blocking effect’ of free charge carriers due to the low mobility of macromolecular chains of the polymer matrix. In the same temperature range, the values of the real part of the complex conductivity vary linearly with frequency, i.e., such systems are insulators. At temperatures higher than Tg, ‘defrosting’ of the polymer chains occurs that leads to the release of lithium cations and growth of ϵ' values. Free lithium cations pass into the conducting band and begin to move along the polymer chain through the interactions with oxygen ether atoms, which exist in macromolecular chains (Figure 4). This charge transfer leads to an increase in the electrical conductivity of the systems and the appearance of a plateau at low frequencies (the so-called DC conductivity plateau, an isotherms area, where conductivity values are independent on frequency) on the spectra of the real part of the complex conductivity. The σ′ dependence on angular frequency ω =2πf is described by the following equation [28, 29]:Figure 3


Electrophysical behavior of ion-conductive organic-inorganic polymer system based on aliphatic epoxy resin and salt of lithium perchlorate.

Matkovska L, Iurzhenko M, Mamunya Y, Matkovska O, Demchenko V, Lebedev E, Boiteux G, Serghei A - Nanoscale Res Lett (2014)

Scheme of lithium cation transfer in the DEG/LiClO4system. The lithium cation transfer along the DEG polymer chain.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493850&req=5

Fig4: Scheme of lithium cation transfer in the DEG/LiClO4system. The lithium cation transfer along the DEG polymer chain.
Mentions: Figure 3 shows the isothermal spectra of the real part of the complex permittivity (ϵ') and the conductivity (σ') for different concentrations of LiClO4 in DEG obtained in the temperature range from −60°C to 200°C. One can see that values and character of the σ' and ϵ' curves depend on two factors: the content of LiClO4 and the temperature of measurements. At temperatures below the glass transition, the permittivity has low values and hardly varies with frequency indicating the ‘blocking effect’ of free charge carriers due to the low mobility of macromolecular chains of the polymer matrix. In the same temperature range, the values of the real part of the complex conductivity vary linearly with frequency, i.e., such systems are insulators. At temperatures higher than Tg, ‘defrosting’ of the polymer chains occurs that leads to the release of lithium cations and growth of ϵ' values. Free lithium cations pass into the conducting band and begin to move along the polymer chain through the interactions with oxygen ether atoms, which exist in macromolecular chains (Figure 4). This charge transfer leads to an increase in the electrical conductivity of the systems and the appearance of a plateau at low frequencies (the so-called DC conductivity plateau, an isotherms area, where conductivity values are independent on frequency) on the spectra of the real part of the complex conductivity. The σ′ dependence on angular frequency ω =2πf is described by the following equation [28, 29]:Figure 3

Bottom Line: The effect of LiClO4 content on the electrophysical properties of epoxy polymers has been studied by differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS).The effect of LiClO4 content on the structure has been studied by wide-angle X-ray scattering (WAXS).The presence of ether oxygen in DEG macromolecules provides a transfer mechanism of the lithium cations with the ether oxygen similar to polyethylene oxide (PEO).

View Article: PubMed Central - PubMed

Affiliation: Institute of Macromolecular Chemistry of National Academy of Sciences of Ukraine, Kyiv, 02160, Ukraine, LOVEMK@ukr.net.

ABSTRACT

Unlabelled: In the present work, ion-conductive hybrid organic-inorganic polymers based on epoxy oligomer of diglycide aliphatic ester of polyethylene glycol (DEG) and lithium perchlorate (LiClO4) were synthesized. The effect of LiClO4 content on the electrophysical properties of epoxy polymers has been studied by differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS). The effect of LiClO4 content on the structure has been studied by wide-angle X-ray scattering (WAXS). It was found that LiClO4 impacts on the structure of the synthesized hybrid epoxy polymers, probably, by formation of coordinative complexes {ether oxygen-lithium cations-ether oxygen} as evidenced from a significant increase in their glass transition temperatures with increasing LiClO4 concentration and WAXS studies. The presence of ether oxygen in DEG macromolecules provides a transfer mechanism of the lithium cations with the ether oxygen similar to polyethylene oxide (PEO). Thus, the obtained hybrid polymers have high values of ionic conductivity σ' (approximately 10(-3) S/cm) and permittivity ϵ' (6 × 10(5)) at elevated temperatures (200°С). On the other hand, DEG has higher heat resistance compared to PEO that makes these systems perspective as solid polymer electrolytes able to operate at high temperature.

Pacs: 81.07.Pr; 62.23.St; 66.30.hk.

No MeSH data available.


Related in: MedlinePlus