Evaluation of the Glass Transition Temperature and Intermolecular Interaction of Poly(ethylene oxide) with Addition of Lithium Perchlorate or/and Titanium Dioxide

Abstract

The high crystallinity of poly (ethylene oxide) (PEO) has urged the need for adding salt or nanofiller. The effect of the glass transition temperature (T_g) and intermolecular interaction of PEO upon the addition of salt or nanofiller become a debatable topic due to the lacking of the understanding of the role of salt or nanofiller in PEO. Hence, the evaluation of the T_g and intermolecular interaction of PEO with addition of lithium perchlorate (LiClO₄) salt or/and titanium dioxide (TiO₂) nanofiller are presented and discussed. The solid polymer electrolytes with addition of nanofiller are prepared by solution casting technique. The optimum composition of PEO and LiClO₄ salt is used as host matrix and TiO₂ as nanofiller. The T_g and intermolecular interaction of the polymer-based electrolytes have been studied by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. PEO-LiClO₄ serves as the classical model of polymer-salt systems with good polymer-salt molecular interaction at low salt concentration (W_S ≤ 0.107) whereas TiO₂ without any surface treatment when added to PEO, serves as a classical model of polymer-nanofiller systems with weak polymer-nanofiller molecular interaction. Results have shown that LiClO₄ salt gives notable effect on the T_g and intermolecular interaction of PEO. Whereas, TiO₂ do not provide a substantial effect on the T_g and intermolecular interaction of PEO-based polymer electrolytes. This work provides a better understanding and knowledge of the effect of addition of salt or/and nanofiller in the T_g and intermolecular interaction of the PEO systems.