The free-radical polymerization of multiple tetrafluoroethylene molecules yields polytetrafluoroethylene, or PTFE. It’s a plastic fluoropolymer with exceptional versatility and a distinctive ivory white and opaque appearance. PTFE finds use in a wide variety of fields, including aerospace, the food & beverage industry, china valve manufacturer firms,
pharmaceuticals, and telecommunications.
PTFE, better known by its brand name Teflon (owned by Chemours), has excellent nonstick qualities and finds widespread use in cookware.
Many top manufacturers produce PTFE in rods or tubes of any size. By adding fillers like glass, graphite, stainless steel, and many others, they are able to boost its wear resistance and strength to make it suitable for virtually any construction or engineering application.
What Is The Function Of PTFE?
Seals (including PTFE ‘O’ rings), PTFE gaskets, insulated transformers, bearings, valves, wire insulation, surface coatings, chemical transport, PTFE bellows, and PTFE rubber diaphragms are only a few of the many uses for PTFE because of its useful qualities.
The Chemical Inertness Of PTFE
Perhaps PTFE’s most remarkable quality is its invulnerability to chemicals. At normal temperature, PTFE is insoluble in all known solvents.
In point of fact, with the exception of a small number of chemical agents such as chlorine trifluoride and elemental fluorine, PTFE’s only true Achilles heel is its very weak resistance to high energy radiation. This causes the dissolution of the PTFE molecule.
Primary PTFE Characteristics
In the absence of PTFE, one would want to design a material that is at least somewhat as good as it is in the areas of flexibility, chemical resistance, thermal resistance, non-stickiness, and electrical resistance.
The melting point of PTFE is somewhere around 327 degrees Celsius, and pure PTFE is virtually completely chemically inert, and highly insoluble in the vast majority of solvents or chemicals. Also, it’s thermally stable enough to be utilized between -200 degrees Celsius and +260 degrees Celsius without deteriorating.
Other advantageous characteristics of PTFE include:
- High flexural strength, which is maintained even at low temperatures
- High electrical resistance and dielectric strength
- Resistance to water (a result of fluorine’s strong electronegativity)
- Low coefficient of friction.
The density of PTFE, at 2200 kg/m3, is likewise quite high.
In point of fact, the only thing that needs to be considered when working with PTFE is that it does not offer good resistance to high-energy radiation, resulting in the breakdown of the PTFE molecule.
This reaction can occur with certain chemical agents and solvents, such as chlorine trifluoride, cobalt(III) fluoride, xenon difluoride, or elementary fluorine if it is subjected to high pressure and temperature.
Basic Characteristics Of PTFE Material
- All other chemicals have no effect on it, but PTFE melts in the presence of chlorine, trifluorides, fluorine, and related fluorine complexes.
- Solvent resistance; insoluble in all common solvents at temperatures up to 260 °C. PTFE expands and dissolves in certain highly fluorinated oils at temperatures near its crystalline melting point.
- PTFE can work at -250 °C to +260 °C (at sea level) which is a large temperature window within which the device can function.
- Extremely low coefficient of friction, even compared to other nonmetals.
Chemical And Mechanical Characteristics Of PTFE
- Very little ability to absorb moisture
- Highly non-inflammable
- Irradiation in air and vacuum which does not significantly alter the material’s resistance to radiation, and its electrical characteristics remain largely unaltered
- Superior durability in adverse conditions
- High-quality electrical insulation and excellent electrical characteristics throughout a wide frequency ranges
Due to the last characteristic, the PTFE material is often used in special pond filtration systems where electrical insulation is important. This is because such electrical filtration systems are often installed in the pond’s base hence, insulation is crucial for the sake of safety.
Alterations Made To The PTFE’s Natural Characteristics
In addition to PTFE in its purest form, two co-polymers on the market share many of the same applications as PTFE but have some key differences.
The first one is the Perfluoroalkoxy (PFA) which is a thermoplastic with good melt-processing, injection-molding, extrusion-molding, compression-molding, blow-molding, and transfer-molding capabilities. It is also very resistant to chemicals and heat (it may be used continuously up to 260 degrees Celsius).
The second one is Polytetrafluoroethylene (also known as PTFE-TFM) with the addition of perfluoropropylvinylether. It creates a denser, stiffer polymer that also creeps resistant like polyphenylene fluoride (PFA) and is weldable.
Impressive Applications For PTFE
In addition to being used as a coating for anything from pans to bearings, PTFE may also be used to prevent insects from climbing walls. This is possible because the substance is so “non-stick” that insects and even geckos cannot get a grip on it.
In addition to its use as a graft material in surgical procedures, the polymer is commonly employed as a coating on catheters to prevent the growth of bacteria and infections.
It is usually considered that the carbon-fluorine bond is the strongest single bond in organic chemistry. As a result of the prevalence of carbon-fluorine bonds in PTFE, the material has high flexural strength and is chemically inert.
It is very resistant to the elements, doesn’t stick to anything, can withstand high temperatures, has the least coefficient of friction of any solid material. As a result, it provides outstanding electrical insulation and dielectric strength.