Post-consumer tyre provide a real challenge for recovery and re-use, since they must be disposed of in an environmentally sound and sustainable manner. Pyrolysis has proved an attractive method. The authors have already established a process of pyrolysis to regenerate the carbon black from waste tyres; it was elaborated in an earlier paper.
The regenerated blacks(RB) have now been characterized by various methods. They were mixed in a typical virgin carcass compound, the required properties of the mixed compounds were measured, and then the compounds were cured under standard conditions of time and temperature. The physico-mechanical properties of the cured specimens were measured and compared to those of samples made using virgin (VB) and heat-treated blacks (HTB). It was concluded that the regenerated black has a higher surface area, and gives a higher elongation at break, with a higher heat build up, lower cure rate and lower modulus than virgin blacks, but a comparable state of cure, dispersion, hardness, tensile strength, tear strength and high adhesion strength. It was also found that regenerated black had a slightly different structure and agglomerate size. Some polar groups were incorporated into the carbon black, either during pyrolysis or during heat treatment. The regenerated black gave better ageing properties than the virgin or heat-treated blacks.
