Why Teflon is so slippery while other polymers are not

Polytetrafluoroethylene [PTFE (Teflon)] is a uniquely slippery polymer, with a coefficient of friction that is an order of magnitude lower than that of other polymers. Though known as nonsticky, PTFE leaves a layer of material behind on the substrate while sliding. Here, we use contact-sensitive fluorescent probes to image the sliding contact in situ: We show that slip happens at an internal PTFE-PTFE interface that has an unusually low shear strength of 0.8 MPa. This weak internal interface directly leads to low friction and enables transfer of the PTFE film to the substrate even in the absence of strong adhesion.

Automated summary

Polytetrafluoroethylene (PTFE) is a highly slippery polymer with a low coefficient of friction compared to other polymers. Despite being nonsticky, PTFE leaves a material residue on the substrate while sliding.