De-vulcanizing Rubber

Automobile tires exemplify the problems with single use rubbers. A very high value product is turned into much lower value products: fuel, oil and carbon black by pyrolysis.
Thermal (microwave) and high shear processes can partly devulcanize the material, which can then be incorporated into new rubber.
EnRoute has developed a mild and rapid process that completely cut all the S-S crosslink bonds.  Complete devulcanization allows recover of carbon black/silica fillers and >90% recovery of the organic material as re-crosslinkable oil. Natural rubber, big rig, consumer tires, bike inner tubes and EPDM all degrade with this process.

The Chemical Process

Functional Crumb

Rather than degrading all the rubber, the process can be utilized to surface fuctionalize crumb, after which it can be used as a reinforcing filler, or on its own to make new rubber by direct molding. 

Media information

The original paper (patent pending) may be found in Green Chemistry  Zheng, S.; Liao, M.; Chen, Y.; Brook, M. A., Dissolving used rubber tires. Green Chem. 2020, 22 (1), 94-102, DOI 10.1039/C9GC03545A.

McMaster video about the process                 The Globe and Mail article Jan. 13, 2020     Chemistry World article, Dec. 17, 2019