Thermal Properties and Morphological Studies of Poly(ethylene oxide) with the Addition of Salt or Nanofiller

Abstract

AbstractThe increasing demand of the functional polymers in the global industry has led to extensive development of new polymeric materials with enhanced properties. This work focuses on the effect of addition of lithium perchlorate (LiClO4) or titanium dioxide (TiO2) on the thermal properties (i.e., glass transition temperature [Tg], change in heat capacity [ΔCP], crystallinity [X*], melting temperature [Tm]) and morphology of poly(ethylene oxide) (PEO) investigated by using differential scanning calorimetry (DSC) and polarized optical microscope (POM). The Tg and ΔCP of PEO at a mass fraction of salt, WS ≤ 0.0196, increase with the addition of salt. Whereas the values of crystallinity and Tm of PEO at the same salt fraction decrease slightly with increasing salt fraction, suggesting the presence of an interaction between the salt molecules and PEO matrix. However, at WS ≥ 0.107, the Tg, crystallinity, and Tm of PEO decrease significantly with the addition of salt, suggesting the phase separation of the binary mixtures of PEO and salt into salt‐rich and salt‐poor phases are developed. This observation is supported by optical inspections where the salt precipitations can be seen. Meanwhile, the values of Tg, ΔCP, crystallinity, and Tm of PEO show insignificant changes with increasing nanofiller fraction indicating no interaction between PEO and the nanofiller. The two‐phase of PEO and nanofiller in the PEO‐TiO2 can be observed clearly from the optical inspection for all PEO‐nanofiller compositions. Hence, the addition of LiClO4 at low content exhibits relatively prominence on the PEO matrix than the TiO2. LiClO4 possesses better molecular interaction with PEO than TiO2 with PEO.