Morphological features, dielectric and thermal properties of epoxy–copper cobaltite nanocomposites: preparation and characterization

Abstract

Epoxy (LY-556/HY-951) system was cured at ambient temperature and its copper cobaltite nanocomposites with different percentage loadings of nanoparticles were prepared via powered shear mixing with HY-951 (triethylene-tetra-amine, TETA) hardener. Characterizations of the nanocomposites were done by various methods like XRD, TEM, FTIR, TGA, DSC, SEM, VNA, DETA and XPS. XRD, XPS and TEM showed the successful preparation of copper cobaltite nanoparticles. Further, FTIR studies confirmed accomplishment of curing and consequently the formation of cross-linked network in the nanocomposites. The morphological analysis revealed that the nanoparticles of the copper cobaltite were uniformly distributed inside the epoxy matrix to 5% loading. The enhancement in impact properties of nanocomposites with increase in filler content was supported by fractured surface studies for even distribution of copper cobaltite nanoparticles. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analyses showed enhancement in thermal stability as well as positive shift in the glass transition temperature for epoxy with copper cobaltite filler in comparison to neat epoxy resin. The positive shift in the glass transition temperature of the nanocomposites indicated improved interaction between copper cobaltite and epoxy matrix. These nanocomposites were also evaluated for their electromagnetic properties using dielectric thermal analyzer (DETA) and vector network analyzer (VNA) for determination of their permittivity and permeability, respectively. The improved thermal, mechanical and electromagnetic properties of epoxy–copper cobaltite nanocomposites make them potential candidates for microwave applications in a wide range of areas.