Exploring the high k dielectric behavior of bio-carbon reinforced cyanate ester nanocomposites

Abstract

In the present work, the surface of bio-carbon (AC) derived from rice husks has been functionalized with 3-aminopropytriethoxysilane. The functionalized bio-carbon (FAC) was then used as a reinforcement for a cyanate ester (CE) matrix to obtain FAC/CE bio-composites. The morphology, thermal, electrical conductivity, and dielectric properties of the FAC/CE bio-composites were studied with respect to the FAC loading. It was found that the introduction of FAC reduces the heat-release rate and increases the degradation temperature, consequently the char residue of the cyanate ester matrix increases. The glass-transition temperature (T_g) obtained infers that the introduction of FAC increases the T_g of the resulting nanocomposites through restricting the mobility of the CE matrix. Moreover, FAC reinforcement improves the overall conductivity and acts as a capacitor in the resulting nanocomposites. Finally, due to its higher capacitive behavior the overall dielectric constant of the developed FAC/CE nanocomposites increased significantly and shows the highest value of the dielectric constant (k = 8.13) for a 4 wt% FAC/CE nanocomposite. The results from thermal and dielectric studies infer that the bio-carbon reinforced CE nanocomposites can be used as embedded capacitors in the interlayers of printed circuit boards (PCBs) and as an electromagnetic interference shielding/antistatic material.