What is Teflon?
The name Teflon itself is a brand name but it has been adopted much like the way we refer to bandaids. Teflon is made of Polytetrafluoroethylene or more easily referred to as PTFE. It is a waxy polymer that is often fabricated into pipes liners, bearings and parts for pumps and valves. It of course is most commonly used to coat our nonstick cookware. PTFE is even used in the aerospace industry to coat wires and other parts on projects such as the International Space Station and Mars Rover.
Properties of Teflon
This material has three very desirable characteristics: (1) it is inert to most chemicals, (2) it has the lowest coefficient of friction of any man made solid at 0.04 and (3) it has a high melting point.
Atomic Structure of PTFE (http://www.substech.com/dokuwiki/doku.php?id=polytetrafluoroethylene_ptfe_as_solid_lubricant)
PTFE is made chemically inert by the fluorine atoms that surround and protect the carbon chains, thus creating strong bonds and a dense molecule. It also has a high melting point of 326° C, which makes it good for cooking surfaces and electrical insulation. The material's extremely low coefficient of friction is one of the most desirable traits as it can be molded into bushing and bearings that do not require lubrication during use.
Surface of a bearing before and after PTFE application (http://images.machinedesign.com/images/archive/ptfeprocess.gif)
As shown in the picture above, a normal machined bearing has a very rough surface on the microscopic level. This roughness allows for more friction and less efficiency from the part. However, it is seen that once PTFE is used to coat the inside of the bearing, the roughness is evened out leaving a nice smooth surface.
Stress vs. Strain Diagram For PTFE (http://www.rjchase.com/ptfe_handbook.pdf)
Deformation vs. Time Under Compression (http://www.rjchase.com/ptfe_handbook.pdf)
While Teflon has a lot of benefits and useful properties it is not a material that performs well under large amounts of stress. This claim is especially true when the temperature of the material is increased. As shown in the stress strain diagram, the yield stress is not very high as compared to other materials such as steel. That being said, this is a plastic and is not expected to handle large loads. The deformation chart above shows a quality known as creep, a phenomena common to plastics. It appears that PTFE responds very little to constant loads over long periods of time. This is a good response which means the material will last longer.
Teflon a.k.a polytetrafluoroethylene is an incredibly useful material that makes everyday life easier and enhances many products and parts. Its unique chemical bonds give it its properties of chemical inertness, low coefficient of friction, and high melting point. Overall Teflon is a material to be desired.
The Editors of Encyclopædia Britannica - Polytetrafluoroethylene (https://www.britannica.com/science/polytetrafluoroethylene)
DuPont Properties Handbook - Teflon PTFE (http://www.rjchase.com/ptfe_handbook.pdf)