The main properties of PTFE
Aug 23, 2023
The main properties of PTFE
If you're trying to invent a material that's highly flexible, chemical-resistant, heat-resistant, non-stick, and electrical-resistant, and it hasn't been done yet, you'd hope you could come up with a material that's almost as good as Teflon in those areas.
PTFE has a melting point of approximately 327°C, and pure PTFE is almost completely chemically inert, highly insoluble in most solvents or chemicals, and thermally stable enough to be used between -200°C and +260°C without degradation .
Other useful properties of PTFE include high flexural strength even at low temperatures, high electrical and dielectric strength, water resistance (due to the high electronegativity of fluorine), and low coefficient of friction. The density of PTFE is also very high at 2200 kg/m3.
In fact, except for reactions with certain chemical reagents and solvents (for example, chlorine trifluoride, cobalt(III) fluoride, xenon difluoride, or elemental fluorine, if under high pressure and temperature), the only time required when using PTFE The consideration is that it does not have good resistance to high-energy radiation, which causes the breakdown of the Teflon molecules.
Properties of modified PTFE
In addition to pure PTFE, there are two other copolymers that serve the same purposes as PTFE, but with some different properties.
PFA, or perfluoroalkoxy, has properties very similar to PTFE, namely very chemically resistant, flexible, and thermally stable (continuous use up to 260°C), but while PTFE does have some tendency to creep, PFA is creep resistant and well suited for melt processing, injection molding, extrusion, compression molding, blow molding and transfer molding.
TFM, known as PTFE-TFM, is a polytetrafluoroethylene containing perfluoropropyl vinyl ether as an additional modifier to provide a denser, stiffer material that is also creep resistant like PFA, And can be welded.
Filled with PTFE
Pure PTFE sheets can deform severely under load, but the use of fillers can help with this, although it should be noted that not all filled PTFEs are suitable for use with food.
Adding fillers to PTFE can increase its strength, improve wear resistance, increase electrical conductivity, etc.; however, adding fillers will also reduce some of the beneficial properties of PTFE, such as chemical resistance, which will be limited by the fillers.
