Effect of thermoplastic polymer in brake pads on particulate matter emission: A case study with polyethylene

The reduction of brake emissions was attempted by adding a small amount of polyethylene (PE) in a low-steel brake friction material. The results indicated that the particle concentration and pad wear were considerably reduced. PE facilitates the formation of friction films on the pad surface, indicating that molten PE promotes wear particle agglomeration at the sliding interface. The friction films on the pad with PE prevent the metallic adhesion of the steel fibres on the pad to the iron disc and decrease the particle concentration and wear of the friction couple, which was confirmed via the analysis of airborne and settled wear particles.