Methods for laboratory-generation and physico-chemical characterisation of tyre wear particles

Tyre wear particles are generated by the frictional forces between a tyre and the road during driving. Tyre wear represents one of the biggest sources of synthetic polymer-based material released into the environment, significantly contributing to microplastic pollution and the associated ecological consequences. However, the extent of tyre particle pollution is not fully understood, and research and understanding are hindered by a lack of described chemical compounds that meet all the criteria for an effective marker of tyre particles. The aims of this study were to develop a methodology for generating tyre particles using a pin-on-disc tribometer; and to distinguish the chemical components in the particles – using two-dimensional gas chromatography-mass spectrometry – to propose a suite of potential markers. The results show that the morphology of the tyre particles reflected that of particles generated in previous literature and during driving. Additionally, the suggested markers were common across the three tyre brands studied here, thus meeting one of the criteria for a successful marker. Future research into measuring the concentration of tyre particles in environmental samples is necessary to understand further their distribution, and assessing the contribution of tyre particles to non-exhaust emissions can inform on future engineering strategies to minimise their release