ON THE DEPENDENCE OF FRICTION FORCE ON SLIDING VELOCITY IN THE THEORY OF ADHESIVE FRICTION OF ELASTOMERS

An improvement of a recent statistical theory of the adhesive friction of elastomers is proposed taking into account the delay in breaking polymeric chains off the wall owing to Brownian oscillations of the terminal segment attached to the wall. This results in the appearance of an S-shape dependence in the curve relating friction force to sliding velocity. The general formulae of the theory are then revised and when the force acting on a single chain depends linearly on its extension, a simple and explicit expression for friction force on sliding velocity is obtained. The applications of the sliding friction dependence to the stick-slip phenomena in flow of molten polymers are also discussed.