Molecular dynamics simulations of amorphous polymer friction behavior

With various temperatures and adhesion strength considered, a scratch test between a conical probe and amorphous polymer film modeled by coarse-grained model (CG) was simulated by molecular dynamics (MD) for exploring the friction behavior of the amorphous polymer. After the polymer chain structure (bond orientation and chain configuration) was studied, the structural dynamics of the polymer at he interface between the tip and the polymer film was explained. If the polymer was in a glassy state for a strongly attractive tip, the bond orientation of polymer chains in the interface oriented in the sliding direction. The gyration tensor, characterization of the chain configuration, increased to about 10 times in the sliding direction compared with that of before sliding. That is, the chain conformation was changed significantly.