Silica Obtained Via Pyrolysis of Waste ‘Green’ Tyres - A Filler for Tyre Tread Rubber Blends

Abstract

A solid product SiO2D has been obtained as a result of subjecting the tread of ‘green’ tyres to pyrolysis-cum-water vapor. It has been found by IR-FTIR and EDXRF spectroscopy that the product contains 65% of SiO2, 30% of carbon, 3% of ZnO, and 2% of other components. The mechanical and dynamic properties, and SEM micrographs of the vulcanizates of model sSBR/BR-based blends having a different SiO2D filler content have been compared to those of vulcanizates filled with conventional SiO2 and carbon black at a 2 : 1 ratio. Composites comprising ZnO as well as such comprising zinc salts of long-chain fatty acids have been investigated. Differences have been established neither in the mechanical properties (Modulus 300, tensile strength, abrasion, etc.) nor in the dynamic properties (heat build-up, tan δ, etc.) of the vulcanizates filled with SiO2D and of those filled with conventional SiO2 and carbon black at a 2 : 1 ratio. The size of SiO2D particles has been found to be the same as that of conventional SiO2. Their distribution in the rubber matrix also does not differ.