STATIC AND KINETIC FRICTION OF STRONGLY CONFINED POLYMER-FILMS UNDER SHEAR

In the present work, we investigate the dependence of relaxational pro cesses in strongly confined polymer liquids as a function of the molec ular mass and of the confining film thickness, both theoretically and experimentally. A qualitative agreement is observed between the theore tical predictions and experimental findings. On the basis of the propo sed theory and experimental data, we estimate the relaxation time of t he polymer segments in the first surface layer and far away from the s urfaces as well as the maximum stress relaxation time.