Effects of silicon dioxide nanoparticles on the mechanical, acoustic and vibration damping properties of kenaf-fibre polyester composite panels

nanoparticles (NPs) in kenaf fibre reinforced polyester resin acoustic panels used for indoor applications. Three variants of the panels were manufactured using Vacuum assisted resin infusion process, each panel consisting of five layers of kenaf fibre with three weight percentages of NPs (0.0, 0.5 and 1.5). Sound Absorption Coefficient (SAC) testing was performed via impedance tube in higher and lower frequency ranges. Tensile testing was carried out using Instron 8801 Universal Testing Machine following ASTM D3039 standard and ASTM D790 standard was used for performing flexural test on a Tinius Olsen H10KL Universal Testing Machine. Free vibration analysis was performed using Atalon-DAQ 042,451. A micro-X-ray computed tomography scan was performed to evaluate the porosity of the panel specimen. Scanning electron microscopy (SEM) images were utilized for studying the dispersion of NPs and other effects. The results showed that the tensile and flexural strength decreased with the addition of NPs with the 1.5% sample showing the lowest tensile strength and flexural strength. The 0.5% sample displayed a SAC of 0.98 at 666 Hz and the 1.5% sample showed the best SAC of 0.99 at 2040 Hz. An increase in void content was observed with an increase in NPs. SEM Imaging revealed the various defects such as agglomerates, debris and cavities. The 0.5% sample showed the highest water absorption capability with an increase of 5.59% in weight. Addition of NPs improved the damping properties of the samples.