Effect of pyrolysis carbon black from waste tires on the properties of styrene-butadiene rubber compounds

Only a few works focus on the use of commercial pyrolysis carbon black (PCB) to replace with commodity carbon black in terms of increasing environmental awareness. In this work, a commercial PCB (ET (Enrestec) black) from waste tires was compared with N660 carbon black in styrene-butadiene rubber (SBR) compounds using standard American Society for Testing and Materials recipes. Particle aggregate size, composition, and surface functionality of ET black and N660 were analyzed through light scattering, energy-dispersive X-ray spectroscopy (EDS), and Fourier transform infrared spectroscopy, respectively. Higher compound viscosity and aggregation power for ET black filler in the rubber matrix was observed. A progressive decrement of approximately 20% in M300 from 15.2 MPa for N660-filled SBR to 12.4 MPa for ET black-filled SBR with increasing ET black ratio in the fillers was clearly observed. ET black could potentially replace 20% in N660 without much influence for SBR compounds in terms of tensile strength. The effect of ET black content on the tear strength was less marginal than the tensile strength. However, with increasing the ET black content, the abrasion resistance index progressively decreased. Thus, it was quite beneficial to consider the merit of PCB in terms of the applications required for tearing resistance. This paves the way for the opportunities to expand further commercial application of PCB from waste tires in the light of environmental awareness.

Automated summary

This study compared commercial pyrolysis carbon black (PCB) from waste tires with N660 carbon black in SBR compounds, finding that the ET black filler had higher viscosity and aggregation power in the rubber matrix. Increasing the ET black ratio led to a gradual decrease in tensile strength of SBR, but it could potentially replace 20% of N660 without significant impact. The influence on tear strength was marginal, but abrasion resistance decreased with higher ET black content.