Morphology of PI–PEO block copolymers for lithium batteries

Cheng, Xue; Meador, Mary Ann B.; Zhu, Lei; Ge, Jason J.; Cheng, Stephen Z. D.; Putthanarat, S.; Eby, R. K.; Khalfan, Amish; Bennett, George D.; Greenbaum, Steve

doi:10.1016/j.polymer.2006.06.024

Cited by 21 publications

(13 citation statements)

References 20 publications

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“…There is also a peak attributed to aromatic interaction or alignment, P aOF, at a length scale of around 15 nm which is expected to impart some rigidity to the material. These PEG and aromatic features are similar to others found in PEG and imide segment systems studied previously …”

Section: Resultssupporting

confidence: 88%

Effects of aromatic regularity on the structure and conductivity of polyimide‐poly(ethylene glycol) materials doped with ionic liquid

Coletta

Toney

Frank

2015

J Polym Sci B Polym Phys

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An understanding of the structure and properties of polymer electrolyte systems can be crucial to a variety of different applications. The current work performs a study of the composition, structure and properties of poly(ethylene glycol) (PEG)-aromatic polyimide systems incorporating ionic liquids that are relevant to several applications especially fuel cell membranes. Composition was varied through using different aromatic dianhydrides, aromatic diamines and in some cases synthesis solvent. Properties were characterized using Fourier transform infrared spectroscopy, thermal gravimetric analysis, differential scanning calorimetry, small-angle x-ray scattering, electrochemical impedance spectroscopy and cyclic voltamme-try. By varying solvent, aromatic regularity and expected rigidity can be tuned, impacting average conductivity by 30%. Varying the aromatic diamine can influence the length scale and amount of aromatic regularity, which can ultimately affect the conductivity by a factor of four. The maximum conductivity reached was 83 mS/cm at 80 C and 70 %RH.

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Section: Resultssupporting

confidence: 88%

Effects of aromatic regularity on the structure and conductivity of polyimide‐poly(ethylene glycol) materials doped with ionic liquid

Coletta

Toney

Frank

2015

J Polym Sci B Polym Phys

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“…This is due to the high crystallinity (up to 70%) for high molar‐mass SPEs . Thus, various approaches have been made to enhance to conductivity of SPEs such as addition of plasticizers and fillers, polymer blending, polymer hosts using copolymers etc. Blending PEO with another component is one of the cost‐effective and convenient ways for the enhancement of the conductivity of SPEs by compositional change of the blends.…”

Section: Introductionmentioning

confidence: 99%

Thermal Properties and Morphology of Poly(ethylene oxide)/Poly(n‐butyl methacrylate) Blends

Ramli

Chan

Ali

2018

Macromolecular Symposia

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From the thermodynamic point of view, most of the high molar‐mass binary polymer blends are immiscible due to the entropic contribution to the free energy of mixing is relatively small. The miscibility of the systems on the molecular scale can be assessed by the thermal properties such as quantities of glass transition temperature (Tg) and change in heat capacity (ΔCp) of the polymers. For a semi‐crystalline polymer such as poly(ethylene oxide) (PEO), the crystallinity (X*) and the melting temperature (Tm) can also give some hints on the miscibility. Apart from the thermal properties, additional scientific findings such as morphology of the blends are needed as supplementary evidences to support the results. We focus on the PEO as the polymer host, blends with poly(n‐butyl methacrylate) (PnBMA) which were prepared using solution casting technique. Thermal properties of PEO/PnBMA polymer blends were investigated by modulated differential scanning calorimeter (MDSC) on the isothermal crystallized samples at 25 °C. Tg of PEO in the blends do not show significant variation with addition of PnBMA for entire composition range while for Tg of PnBMA in the blends, it is challenging to be estimated under the experimental condition due to the overlapping of the Tg of PnBMA and melting endotherm of PEO. Constancy of quantity Tg of PEO and ΔCp of PEO corresponding to the content of PEO in the blends suggest that PEO and PnBMA are immiscible for entire blend composition. X* and Tm of PEO in the blends show insignificant variation in PEO/PnBMA blends, when PEO as major component. This implies that these blends are immiscible under the experimental conditions as agreed with results of Tg and ΔCp. Spherulitic morphologies of PEO in the blends were studied by polarized optical microscopy (POM). PnBMA phase disperses randomly in PEO matrix when PEO in excess. The absence of significant change for the fibrillar spherulitic structures of PEO spherulites with addition of PnBMA (when PEO is the major component) suggests that immiscibility of PEO and PnBMA. Besides, the crystalline structure of PEO in PEO/PnBMA blends using X‐ray diffraction (XRD) reveals that the crystalline structure of PEO is not disturbed with the addition of PnBMA when PEO is in excess as the two distinct peaks of PEO do not shift as compared to neat PEO. Impedance spectroscopy (IS) studies show that the ionic conductivities (σDC) of the polymer blends at room temperature slightly increase with increasing of PEO with the order of magnitude of 10−11–10−10 S cm−1. This system serves as a potential polymer host as solid polymer electrolytes when added with inorganic salt.

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“…: the classic solid polymer electrolytes (SPEs) with lithium salt dissolved in poly(ethylene oxide) (PEO), display low conductivity ( σ DC ∼10 −5 S cm −1 ), which do not exhibit sufficient conductivity ( σ DC ∼ 10 −3 S cm −1 ) for applications. Therefore, not only PEO has been used as the polymer host in SPEs, but also PEO‐based blends were studied for enhancement of the conductivity. For example, immiscible blend of PEO/epoxidized natural rubber (ENR)/Li blends, PEO/polystyrene (PS)/Li blends and PEO/modified natural rubber/Li blends were studied.…”

Section: Introductionmentioning

confidence: 99%

Thermal Properties and Intermolecular Interaction of Blends of Poly(ethylene oxide) and Poly(methyl acrylate)

Halim

Chan

Sim

2016

Macromolecular Symposia

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Summary Polymer blends of poly(ethylene oxide) (PEO) and poly(methyl acrylate) (PMA) were prepared by solution casting method. Thermal stability of the binary PEO/PMA blends was examined by termogravimetric analysis (TGA). Decomposition temperatures of the binary blends were estimated from the onsets of the weight loss curves of TGA thermograms. The decomposition temperatures of the blends increase when the content of PEO elevates. Hence, PEO has a better thermal stability as compared to PMA. The activation energy of thermal decomposition of each sample was calculated from the initial stage of the decomposition. Quantities of EA increase when content of PEO increases in the blends. Differential scanning calorimeter (DSC) was used to investigate the thermal properties of binary PEO/PMA blends. An existence of a single and composition‐dependent glass transition temperature (Tg) for the blends indicates the miscibility of the PEO/PMA blends. The Tgs of PEO/PMA blends increase when PMA content increases. Furthermore, when PMA is blended with PEO, the crystallinity (X*) and melting temperature (Tm) of PEO in PEO/PMA blends are depressed. Thus, the miscibility of the blends in the molten state is in agreement with Tg results. Fourier‐transform infrared (FTIR) spectroscopy was used to study the intermolecular interaction of between PEO and PMA in the blends. The characteristic absorbance bands of ether and carbonyl groups of PEO and PMA were examined by FTIR. PEO and PMA only display weak van der Waals interactions in blends. Hence the miscibility of PEO and PMA in the blends may be more towards the entropic effect instead of the enthalpic effect.

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Morphology of PI–PEO block copolymers for lithium batteries

Cited by 21 publications

References 20 publications

Effects of aromatic regularity on the structure and conductivity of polyimide‐poly(ethylene glycol) materials doped with ionic liquid

Effects of aromatic regularity on the structure and conductivity of polyimide‐poly(ethylene glycol) materials doped with ionic liquid

Thermal Properties and Morphology of Poly(ethylene oxide)/Poly(n‐butyl methacrylate) Blends

Thermal Properties and Intermolecular Interaction of Blends of Poly(ethylene oxide) and Poly(methyl acrylate)

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