Newly developed biodegradable polymer nanocomposites of cellulose acetate and Al2O3 nanoparticles with enhanced dielectric performance for embedded passive applications

Abstract

In this study, biopolymer nanocomposites of cellulose acetate (CA) and Al2O3 nanoparticles (Al2O3 NPs) were successfully obtained using solution blending method. The effect of Al2O3 NPs loading on the microstructure, morphology, thermal and dielectric properties of CA/Al2O3 nanocomposites was investigated using FTIR, XRD, TGA, optical microscopy, SEM, AFM and impedance spectroscopy technique. The FTIR results infer good interaction between CA and Al2O3 NPs. The XRD and microscopic studies demonstrated that Al2O3 nanoparticles were homogeneously dispersed in the CA matrix. The TGA results indicate that the onset degradation temperature of CA/Al2O3 nanocomposites is shifted towards higher temperature in the presence of Al2O3 NPs. The contact angle measurements infer reduction in the wettability of CA matrix with increasing Al2O3 NPs loading. On the other hand, the dielectric properties of CA were improved due to an incorporation of Al2O3 NPs. The dielectric constant increases from 8.63 (50 Hz, 30 °C) for neat CA matrix to 27.57 (50 Hz, 30 °C) for CA/Al2O3 nanocomposites with 25 wt% Al2O3 loading. Similarly, the dielectric loss also increases from 0.26 (50 Hz, 30 °C) for neat CA matrix to 0.64 (50 Hz, 30 °C) for CA/Al2O3 nanocomposites with 25 wt% Al2O3 NPs loading. However, very low values of tan δ (below 1) were observed for all the samples. These results suggest that CA/Al2O3 nanocomposites with improved dielectric properties seem to be a promising candidate for designing electronic devices such as embedded passives.