The effect of thermally developed SiC@SiO2 core-shell structured nanoparticles on the mechanical, thermal and UV-shielding properties of polyimide composites

Abstract

SiC@SiO2 core-shell nanostructured particles were successfully prepared via simple thermal treatment. The structure of the surfaces of pristine SiC and SiC@SiO2 core-shell nanostructured particles was investigated by X-ray diffraction spectroscopy (XRD). The formation of SiO2 shell on the SiC core was further evaluated by FTIR, SEM, XPS and TEM techniques. The nanostructured particles prepared were amino-modified by APTMS and incorporated in polyimide (PI) matrix to prepare highly flexible composite films. The mechanical, thermal, UV-shielding and water proof properties of the composites were investigated. The TGA results displayed that T5 (5% weight loss temperature) and T10 (10% weight loss temperature) were meaningfully enhanced up to 56.0 °C and 53.4 °C, respectively upon adding various amounts of modified SiC@SiO2 nanoparticles into the PI matrix. DSC results revealed that the glass transition temperature (Tg) was considerably enhanced up to 45.50 °C, up on the incorporation of different dosages of SiC@SiO2–NH2 nanoparticles in the matrix. The tensile results shown that introduction of the nanoparticles into the PI medium exhibited highly significant improvement in the tensile strength and the Young's modulus over 77.1% and 96.6% respectively as compared to the neat PI. The incorporation of SiC@SiO2–NH2 nanostructured particles in the matrix highly improved the hydrophobicity of the composites up to 62.55% as compared to the neat PI. The UV-shielding properties were also enhanced when functionalized SiC@SiO2–NH2 was added to the PI matrix. The dispersion of SiC@SiO2 in the PI matrix was investigated by Scanning electron microscope (SEM).