The Effect of Microstructure on the Mechanical Properties of Devulcanized Waste Tires

With the development of the automotive industry, waste tire production has also increased significantly. And their accumulation causes many problems and occupies a large space. One of the most effective solutions is recycling waste tires by devulcanization, which is more economical than re-production. This paper aims to investigate the relationship between microstructure and physio-mechanical properties of devulcanized rubber samples. For this purpose, mechanical tests and identification tests including FTIR (Fourier-transform infrared spectroscopy) and NMR (Nuclear Magnetic Resonance) were performed on the samples. It was determined that; there is an inverse relationship between sol weight fraction and NR/SBR ratio; the lower the ratio, the higher the vinyl bonds, tensile strength, and swelling index of the specimens, and the better the curing. On the other hand, increasing this ratio decreases the percentage of devulcanization. Therefore, the low NR/SBR ratios will increase the process efficiency and improve the mechanical quality of the devulcanized rubbers.