The interfacial shear stress of toluene cast poly(2,6-dimethyl-1,4-phenylene oxide) films has been studied as a function of annealing temperature. The surface topography of these films was studied by scanning probe microscopy following a single sliding pass. Casting from toluene results in a semicrystalline film with a rigid amorphous phase and containing a small amount of residual solvent that exhibits a higher interfacial shear stress than a high temperature annealed solvent-free amorphous film. Films containing small amounts of toluene exhibit a wear pattern consisting of ripples oriented perpendicular to the sliding direction following a single sliding pass. These results support the notion that the interfacial shear stress is a function of the shear yield stress, and, that during sliding friction tensile stresses must form at the polymer surface. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1637-1643, 2009