Polytetrafluroethylene (PTFE) is made entirely of carbon and fluorine, giving it a high molecular weight. It is a synthetic fluoropolymer of tetrafluoroethylene and is hydrophobic (not wetable) due to the strong electronegativity of the fluorine.
Compared to other solids, PTFE has one of the lowest coefficients of friction. It therefore finds use in a number of cooking applications as ingredients won't stick to PTFE coatings. Its strong carbon-fluorine bonds make it very non-reactive and so it is often employed in pipelines containing particularly corrosive and reactive chemicals. PTFE can also be used in machinery as a lubricant, reducing wear, friction and energy consumption. Modifying PTFE can improve its properties.