Technical Notebook: Upgrading rC for equivalent performance in existing carbon black applications

The emergence of the circular economy has brought new emphasis on tire recycling, and pyrolysis has emerged as a leading technology. Pyrolysis of waste tires creates two usable streams: tire pyrolysis oil (TPO) and reclaimed carbon (rC), which can be substituted for carbon black (CB) in limited rubber formulations.

We examine the rubber properties achievable with commercial first generation Gen1 rC. We show that, without further upgrading, these materials cannot satisfy the demanding performance targets of tire technology. We then present two examples of proprietary Cabot routes for upgrading rC, targeting semi-reinforcing CB (Example 1) and reinforcing CB (Example 2).

In Example 1, we demonstrate iso-dispersion and similar rubber properties to N550 CB at a loading of 26 percent. Example 2 comes close to emulating the performance of N330 at a loading of 20 percent, with some demonstrated tunability in performance. Some challenges remain in tensile properties and dispersion. We hope that with further work these loadings can be increased further.