A fluoropolymer is a fluorocarbon-based polymer with multiple carbon–fluorine bonds. It is characterized by a high resistance to solvents, acids, and bases. The best known fluoropolymer is polytetrafluoroethylene under the brand name "Teflon," trademarked by the DuPont Company.
In 1938, polytetrafluoroethylene ( DuPont brand name Teflon) was discovered by accident by a recently hired DuPont Ph.D., Roy J. Plunkett. While working with tetrafluoroethylene gas to develop refrigerants, he noticed that a previously pressurized cylinder had no pressure remaining. In dissecting the cylinder, he found a mass of white solid in a quantity similar to that of the tetrafluoroethylene gas. It was determined that this material was a new-to-the-world polymer. Tests showed the substance was resistant to corrosion from most acids, bases and solvents and had better high temperature stability than any other plastic. By early 1941, a crash program was making substantial quantities of PTFE for the Manhattan Project. [1] [2] [3] [4]
Fluoropolymers share the properties of fluorocarbons in that they are not as susceptible to the van der Waals force as hydrocarbons. This contributes to their non-stick and friction reducing properties. Also, they are stable due to the stability multiple carbon–fluorine bonds add to a chemical compound. Fluoropolymers may be mechanically characterized as thermosets or thermoplastics. Fluoropolymers can be homopolymers or Copolymer. [ citation needed]
Fluoropolymer | Trade names | Monomers | Melting point (°C) |
---|---|---|---|
PVF (polyvinylfluoride) | Tedlar [5] | VF1 | 200 [6] |
PVDF (polyvinylidene fluoride) | Kynar [7] Solef [8] Hylar [9] | VF2 | 175 |
PTFE (polytetrafluoroethylene) | Sold by AGC under the tradename Fluon PTFE; Sold by Dupont and Chemours Company under the tradename Teflon; sold by Solvay Specialty Polymers under the tradenames Algoflon Hyflon and Polymist; sold by Daikin under the tradename Polyflon | TFE | 327 |
PCTFE (polychlorotrifluoroethylene) | Kel-F ( 3M), Neoflon ( Daikin), Voltalef [10]( Arkema) | CTFE | 220 [6] |
PFA, MFA [11] (perfluoroalkoxy polymer) | Sold by AGC under the tradename Fluon PFA. Sold by DuPont under the tradename Teflon-PFA. Sold by Solvay Specialty Polymers under the tradename Hyflon. [12] Neoflon ( Daikin) | PPVE + TFE | 305 |
FEP (fluorinated ethylene-propylene) | Sold by DuPont under the tradename Teflon FEP. Also known as Neoflon ( Daikin) and Hyflon | HFP + TFE | 260 |
ETFE (polyethylenetetrafluoroethylene) | Sold by AGC under the trade name of Fluon ETFE [13] Tefzel,; [14] sold by Daikin under the tradename Neoflon | TFE + E | 265 |
ECTFE (polyethylenechlorotrifluoroethylene) | Halar [15] sold by Solvay Specialty Polymers | CTFE + E | |
FFPM/ FFKM (Perfluorinated Elastomer [Perfluoroelastomer]) | Kalrez. [16] Tecnoflon PFR [17] DAI-EL ( Daikin) | ||
FPM/FKM (Fluoroelastomer [Vinylidene Fluoride based copolymers]) | Viton, [18] Tecnoflon FKM, DAI-EL ( Daikin), Fluonox (Gujarat Fluorochemicals Limited) | ||
FEPM (Fluoroelastomer [Tetrafluoroethylene-Propylene]) | Sold by AGC under the trade name of AFLAS, [19] | TFE + P | |
PFPE (Perfluoropolyether) | Sold by DuPont under the tradename Krytox. [20] Sold by Solvay Specialty Polymers S.p.A. as Fomblin and Galden | ||
PFSA (Perfluorosulfonic acid) | Nafion | ||
Perfluoropolyoxetane |
Property | Method No. | Units | PTFE | FEP | PFA | ETFE | ECTFE | PCTFE | PVDF |
---|---|---|---|---|---|---|---|---|---|
Specific gravity | D792 | - | 2.17 | 2.15 | 2.15 | 1.7 | 1.7 | 2.15 | 1.78 |
Yield strength | D638 | MPa | 10 | 12 | 15.5 | 24 | 31 | 40 | 46 |
Yield strength | D638 | PSI | 1,450 | 1,740 | 2,250 | 3,480 | 4,500 | 5,800 | 6,670 |
Elongation | % | 200-500 | 250-350 | 300 | 200-500 | 200-300 | 80-250 | 20-150 | |
Tensile modulus | D638 | MPa | 600 | 500 | 700 | 1500 | 1655 | 1500 | 2400 |
Tensile modulus | D638 | ksi | 87 | 72.5 | 101.5 | 217.5 | 240 | 218 | 348 |
Hardness | D2240 | Shore D | 60 | 57 | 62 | 75 | 75 | 90 | 79 |
HDT, @ 66 PSI | D648 | °F | 250 | 158 | 164 | 219 | 240 | 248 | 300 |
HDT, @ 264 PSI | D648 | °F | 122 | 129 | 118 | 160 | 169 | - | 239 |
Limiting oxygen index | D2863 | % | >95 | >95 | >95 | 30-36 | |||
Dielectric constant | D150 | 1 MHz | 2.1 | 2.1 | 2.1 | 2.6 |