Sliding Friction of Rubber

In this paper, we discuss the sliding friction of rubber. We first introduce the outlines of adhesive and hysteretic friction and raise some problems to elucidate the detailed mechanisms. Then we discuss other phenomena, such as hydrodynamic lubrication in wet conditions and inertia-induced abnormal deformation at ultra-high sliding speeds. Throughout these topics, we will stress the importance of in-situ visualization of frictional interfaces.