Utilizing Recovered Carbon Black as a Reinforcing Agent for Ethylene Propylene Diene Rubber Formulation

The environmental risks caused by accumulated rubber wastes have increased the need of recovering these wastes rather than disposing of them. Pyrolysis of waste rubber is recognized as a promising technique. While pyrolysis products oil and gas have previously found industrial applications, there is currently a shortage of viable applications for the solid pyrolysis residue, recovered carbon black (RCB). This study examines the potential use of the RCB as a substitute for virgin carbon black (VCB) in Ethylene Propylene Diene (EPDM) rubber formulation. The goal of this research is to expand technical understanding about the use of the RCB as a green raw material in the rubber industry. In order to characterize the VCB and RCB, Scanning Electron Microscopy (SEM), Energy dispersive X-ray (EDX), Fourier Transform Infrared (FTIR) analyses, and standard test methods were used. The compounds were produced by replacing the VCB with RCB in the EPDM matrix at various loadings. The influence of the RCB addition on the rheological, physical, mechanical and thermal properties of the EPDM composites was evaluated and compared to those formed with the only VCB. The RCB filled compounds usually show detectably inferior properties compared to the only VCB filled compound due to more impurity content, less active surface area, and limited surface functionality of the RCB filler. Although, the VCB can’t be completely replaced by the RCB, the results showed that overall performance of the 75-25 compound is better than the reference compound with 100% VCB filler. Moreover, the more RCB may be utilized in combination with the VCB depending on the permissible deviations from the properties of the end products.