Toward multifunctionality of PEO/PMMA/MMT hybrid polymer nanocomposites: Promising morphological, nanostructural, thermal, broadband dielectric, and optical properties

Abstract

Different compositional ratio organic polymer blend (PB) matrices of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) and these matrices with inorganic montmorillonite (MMT) nanoclay dispersed PEO/PMMA/MMT hybrid polymer nanocomposites (HPNCs) were prepared through solution-cast followed by melt-press technique. The structures and properties of these PB and HPNCs were comprehensively characterized using several advanced techniques: scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, broadband dielectric spectroscopy (2×101–109 Hz), and ultraviolet–visible (UV–Vis) spectroscopy. The effects of PEO/PMMA blend compositional ratio and the MMT nanofiller concentration on the homogeneity, nano- to micro-sized structures of these PBs and the hybrid composites, variation in intercalated MMT structures, melting temperature of PEO crystallites, and degree of crystallinity were explored. Dielectric dispersion and relaxation processes, electrical conductivity, UV–Vis absorbance with energy band-gap, and other optical parameters of these nanocomposites were influenced by the amounts of constituents and polymer–polymer and polymer–nanofiller interphases in these PB and HPNC materials. The dielectric results showed that these materials were low-permittivity nanodielectrics over a wide radio-frequency range (∼105–109 Hz), but a considerable increase in dielectric permittivity with the decrease in frequency from 105 to 2×101 Hz was predominantly governed by the interfacial polarization which confirmed them as tunable-type dielectrics. The promising multifunctional macro-scale properties and their relationship with the nano-scale structural variables indicated that these state-of-the-art engineered HPNCs were flexible and tunable nanodielectrics and also controllable optical properties smart-materials for advances in polymer-based device technologies.