Pyrolytic carbon: factors controlling in-rubber performance

Abstract

Pyrolysis of waste tyres not only tackles the environmental issues associated with disposal, but also enables the recovery of valuable products such as oils and carbon fillers for elastomeric materials. This study was instigated to benchmark the in-rubber properties of pyrolytic carbon (often referred to as pyrolysis carbon black, pCB) and to understand the compositional parameters that dictate performance. Colloidal properties suggest the pCB materials to have a reinforcing potential between that of N330 and N550 carbon blacks, whereas physical property data suggest that they are more akin to the N700 series. Fundamentally, this disparity in performance appears to be the result of carbonaceous residues on the pCB surface, which both reduce surface activity and dispersability of the recyclate. Both thermogravimetric and dynamic mechanical analyses confirmed a number of pCB samples to have the same specific surface activity, regardless of the pyrolysis process or feedstock utilised.