Green composite friction materials: A review of a new generation of eco-friendly brake materials for sustainability

Particulate matter (PM) still poses a significant threat leading to air pollution which is responsible for continued damage to human health and the environment. Particulate matter resulting from non-exhaust emissions are considered as viable a source comes mostly from brake pad wear concept. The scientific challenge of this work is to stimulate a new generation of green friction materials to reduce particle emissions having low-environmental impact. The specificity of braking materials, their effects on the environment and human health are studied. To minimize the levels of air pollution, the use of green friction composites collected from natural elements reducing human diseases is discussed. For this purpose, the novel and high-performance friction composite materials synthesized from vegetable and animal waste used as a raw material are reported. The natural powder and fiber treatments, the optimum formulation and the binder materials related to the green friction composites are reviewed. An overview of environmentally ecofriendly green friction materials embedded by reinforcing phases of natural elements exhibiting excellent mechanical and tribological properties are mentioned. Therefore, scientific and industrial efforts should concentrate on the development of green friction materials to minimize the effect of transport related air pollution.