Modification of polymer electrolytes based on poly(ethylen oxide) and lithius bis(oxalato)borate to improve ionic conductivity : bachelor thesis

Ovaj rad bavi se ispitivanjem utjecaja dodatka litijevog montmorilonita (LiMMT) na toplinske prijelaze (staklište i talište) i kristalnost poli(etilen-oksida). Primijenjene su metode diferencijalne pretražne kalorimetrije (DSC) i infracrvene spektroskopije s Fourierovom transformacijom (FT-IR). LiMMT pripremljen je metodom ionske izmjene iz prirodnog montmorilonita, a polimerni nanokompoziti PEO10/LiMMT/LiBOB s masenim omjerima PEO10/LiMMT 95/5, 90/10, 80/20, 70/30, 60/40 pripremljeni su metodom interkalacije iz taljevine. Sol litijevog bis(oksalato)borata (LiBOB) dodana je u omjeru 1:8 (Li : kisik iz PEO) s ciljem ostvarivanja dovoljne koncentracije nositelja naboja u elektrolitu. Metodom diferencijalne pretražne kalorimetrije (DSC) ispitivan je utjecaj LiMMT-a na toplinske prijelaze (staklište i talište) i kristalnost PEO-a. Utvrđeno je da dodatak LiBOB-a u potpunosti narušava kristalnost uzoraka do 30 mas.% LiMMT, a uzorci s 30 i 40% LiMMT-a pokazali su kristalnu fazu s talištem koje je niže od tališta čistog PEO-a. Metodom infracrvene spektroskopije s Fourierovom transformacijom (FT-IR) ispitivan je utjecaj LiMMT-a na strukturu PEO-a. Utvrđeno je da se dodatkom LiMMT-a narušava spiralna konformacija kristalne faze izvornog PEO-a.This paper examines the impact of lithium bis(oxalato)borate (LiBOB) filler on thermal transitions (glass transition temperature, melting temperature) and crystallinity od poly(ethylene-oxide). Differential scanning calorimetry (DSC) and Fourier Transformation Infrared Spectroscopy (FT-IR) have been applied. LiMMT was prepared by ion exchange method from natural montmorillonite, and polymeric nanocomposites PEO10/LiMMT/LiBOB with different weight ratios PEO/LiMMT 95/5, 90/10, 80/20, 70/30 and 60/40 were prepared by the melt intercalation method. Salt of lithium bis(oxalato)borate (LiBOB) was added in a ratio of (1:8 Li : oxygen of ether) to achieve a sufficient concentration of the charge carrier. Differential scanning calorimetry (DSC) analysis investigate the influence od LiMMT on the thermal transitions (glass transition temperature, melting temperature) and crystallinity of PEO10. It was found that the addition of LiBOB completely destroys the crystallinity of the samples up to 30 % of LiMMT. Samples with 30 % and 40 % of LiMMT showed a crystalline phase with a melting point that is lower than the melting point of original PEO. Fourier Transformation Infrared Spectroscopy (FT-IR) investigate the influence LiMMT on the PEO10 structure. It was found that the addition of LiMMT causes distortion of the spiral conformation of the crystalline phase of the original PEO