Upgraded waste tyre pyrolytic char for solid tyre tread compounds

Abstract

The objective of this study was to evaluate the treatment method of PT-char for the performance of solid tyre tread compounds. The metallic particles in the PT-char were removed by the magnetic separator and the particle sizes were reduced ≤50 μm. PT-char with reduced particle size was demineralized using two treatment methods to get the carbon black (CB) which is used for the preparation of solid tyre thread compounds. The 2M 2H sample was prepared with two washes using 2M HCl, and the 2M 2H-2M S sample was prepared with two washes of 2M HCl followed by one wash with 2M NaOH. The char: acid/base volume ratio was maintained at 1:2, and the treatment was carried out at temperatures ranging from 60 °C to 80 °C for 0.5 to 1 hour stirring. Pyrolytic char and all of the purified samples were characterized by elemental analysis, TGA, XRD, and SEM. These purified CB samples were used to prepare solid tyre tread compounds and their characteristics were evaluated. The highest purity with 91% carbon and 3.5% ash contents was observed for 2M 2H-2M S and Crude CB has 67% of carbon and 83% of carbon content in 2M 2H. The compounding test results indicated that 2M 2H-2M S sample has better performances (Tensile strength: 22.15 MPa, Tear Strength: 69.19 MPa, Hardness: 56.00 IRHD, Compression set: 5.61 %) compared to PT char and comparable to the commercial grade carbon black N330 and N660. This suggests that the current PT-char modification protocol might be a promising route to replace commercial carbon black in solid tyre industry.