The analysis of experimental amplitude and phase curves and phase images of polymer blends was performed in combination with KBM (Krylov-Bogoliubov- Mitropolsky) modelling of tapping mode atomic force microscopy (AFM). Different phase and dissipation contrast of images of multilayer polymer blends suggests that phase imaging is better for compositional mapping whereas understanding of the dissipative processes will facilitate a quantitative description of tip-sample force interactions in this mode. The KBM model describes tapping mode amplitude and phase curves in terms of three stationary solutions (two stable nodes, one saddle) verified by the experiment. A simple model of energy dissipation (adhesion avalanche) was also considered.