Research, development and testing of brake pad materials from biomass-based nanocomposites.

Abstract

Many variables affect braking systems in the automotive industry, including component geometry, brake materials, component interactions, and various operating conditions. The current research trend in the automotive industry is to use waste as raw material for nanocomposite materials in automobile applications. A novel bio-based hybrid nanocomposite (BHN) brake pad has been developed and investigated to serve as a functional replacement for metallic, ceramic, and hazardous asbestos-based brake pad materials. Carbon-based nanocomposites such as carbon nanospheres, carbon nanotubes, carbon nanosheets, and carbon nanofibers, etc., have attracted wide attention from researchers since their discovery. Carbon nanospheres (CNSs) are among the novel carbon nanostructures distinguished for their potential use in many areas, for instance lithium-ion batteries, electrodes in super capacitors, different parts of automobiles and adsorbents. In this study, CNSs were synthesized from palm kernel fiber (PKF) activated carbon using a simple physical activation method under CO2. The BHN consisted of a matrix of carbon nanomaterials from PKF which acted as the filler material, epoxy resin which acted as the binder material, together at a nanoscale to produce brake pad. The temperature effect on synthesized nanomaterials was investigated using transmission electron microscopy (TEM), x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), Fourier transform infrared microscopy (FTIR), and thermo-gravimetric analysis (TGA). The SEM results showed the highest purity, and the largest number of CNSs were formed at a synthesis temperature of 1000 °C. The tribological properties of BHN brake pads were studied and compared with conventional (CON) brake pad material. The BHN brake pads exhibited low wear rate compared to the CON brake pads, while the coefficient of friction (COF) of the BHN brake pad samples (0.3 to 0.5) were within the SAE J661 CODE standard. The results showed that the brake pad performance differed with each pad formulation. The BHN brake pad material had excellent performance in most of the analyses when compared to the CON brake pad material. The mechanical properties of the BHN brake pad such as compressive strength, compressive modulus, hardness and impact strength were tested. The nanocomposite material showed a higher impact strength and compressive strength compared to the (CON) brake pads. The hardness of the material of the two brake pads was statistically akin. Furthermore, the performance of oil and water absorption, thermal stability as well as degradation of the BHN brake pad were determined. The results showed that the BHN brake pad material had low oil absorption rate and low moisture water absorption rate. The BHN brake pad showed thermal stability within the range 300 °C to 400 °C, which are within the standard temperature range. Result from SEM analysis carried out on the worn surfaces of the BHN brake pads reveals a tougher structure than SEM of the worn surfaces of the CON brake pads. Dynamic mechanical analysis (DMA) results showed that at a temperature between 55 °C and 105 °C, the 𝑇𝑎𝑛 𝛿 magnitude of BHN was higher due to the loss modulus supremacy over the storage modulus. In addition, in the temperature range 105 °C to 190 °C, the storage modulus and the loss modulus was as low as that of the CON, and the BHN 𝑇𝑎𝑛 𝛿 magnitude reduced. Excellent mechanical and tribological properties of BHN brake pad was achieved at 0.3 % CNS.