Perfluoroalkoxy properties

Properties Unfilled Flexible Mineral-filled Granular Glass-fiber- reinforced Perfluoroalkoxy... 

Perfluoroalkoxy (PFA) is very like PTFE with very similar fluorine content and properties, but it is melt processable and more expensive. 

Modified PTFE — Copolymer of TFE and a small amount (less than 1%) of other perfluorinated monomer (e.g., perfluoroalkoxy monomer) exhibiting considerably improved physical properties, moldability, and much lower microporosity. 

Teflon PFA (perfluoroalkoxy). This plastic is translucent and slightly flexible. It has the widest temperature range of the fluoropolymers — from -270°C to +250°C — with superior chemical resistance across the entire range. Compared to TFE at +277°C, it has better strength, stiffness, and creep resistance. PFA also has a low coefficient of friction, possesses outstanding antistick properties, and is flame-resistant. 

Perfluoroalkoxy resin (PFA) is a copolymer of TFE and perflnoropropy-1 vinyl ether (PPVE) in a mole ratio of approximately 100 1. Even snch a small amonnt of comonomer is snflicient to prodnce a copolymer with a greatly rednced crystallinity. The relatively long side chains also markedly rednce the cold flow. Methylflnoroalkoxy resin (MFA), a copolymer of TFE and perfln-oromethylvinyl ether (PMVE), has similar properties with a somewhat lower melting point. 

Perfluoroalkoxy resin (PFA) Copolymer of tetrafluoroethylene (TFE) with perfluoro(propylvinyl ether), an engineering thermoplastic characterized by excellent thermal stability, release properties, low friction and toughness. Its performance is comparable to poiytetrafluoroethylene (PTFE) with the difference that it is melt processible. 

Figures 3.34 and 3.35 show the relationship of tensile strength and ultimate (break) elongation with temperature for perfluoroalkyl vinyl ether modified perfluoroalkoxy polymer (PFA). Figures 3.36 through 3.38 show a comparison of the properties of PFA with MFA, which is perfluoromethyl vinyl ether (PMVE). The common measurement technique for tensile properties of fiuoropiastics is ASTM D1708.

The high-polymeric linear phosphazenes are potentially useful materials as far as physical and mechanical properties are concerned, but they have been generally useless because of chemical (especially hydrolytic) instability. Recently, use of perfluoroalkoxy and other side groups has given promise that useful polymers may yet be developed.47 b> 51... 

The macromolecule of perfluorinated alkoxy (PFA) or simply perfluoroalkoxy is based on the monomer unit [—(CFj) —CF(0—C F, )—(CFj) —] . Perfluoroalkoxy is similar to other fluorocarbons such as polytetrafluoroethylene and fluorinated ethylene propylene regarding its chemical resistance, dielectric properties, and coefficient of friction. Its mechanical strength. Shore hardness, and wear resistance are similar to PTFE and superior to that of FEP at temperatures above ISO C. PFA has a good heat resistance from -200 C up to 260°C near to that of PTFE but having a better creep resistance. 

In Table 5.9 the mechanical, thermal, and electrical properties of virgin and 20% glass fiber-reinforced perfluoroalkoxy ethylene are compared. 

Properties of Unreinforced and 20% Glass Fiber-Reinforced Perfluoroalkoxy Ethylene... 

FEP contains CFj side groups due to copolymerisation with 10-12% hexafluoropropylene. The side groups tend to lock together and improve mechanical properties at processable molecular weights. FEP can be processed by extrusion, and its creep performance is better than that of PTFE. However steric stress due to the bulky side group reduces the CUT from 260 to 200 °C. PFA introduces a perfluoroalkoxy side chain - typically OC3F7. PFA can be injection moulded. Both PFA and FEP have PTFE-like chemical resistance and... 

Read et al. synthesized surface-active derivatives of 1,2,3-triazole 49,50 containing at the nitrogen atom perfluoroalkyl (lipophilic) substituents, and at the carbon atom perfluoroalkoxy or alkoxy (hydrophilic) groups. It is significant that the surfactant properties of these compounds can be purposefully regulated varying the length of the fluoroalkyl chain [49, 50],... 

Sugimori T, Horike SI, Handa M, Kasuga K (1998) Preparation and some properties of perfluoroalkoxy-substituted phthalocyanine complexes of iron(lll), nickel(ll) and zincfll). Inorg Chim Acta 278 253-255... 

Perfluoroalkoxy Resin (PFA) A class of melt-process-able fluoroplastics in which perfluoroalkyl side chains are connected to the fluorocarbon backbone of the polymer through flexible oxygen linkages. PFA resins have the desirable properties associated with fluoroplastics plus superior creep resistance, and are more easily processed by extrusion and injection molding. 

One of the disadvantages of PTIE is that it is not melt processable. In 1960 DuPont introduced fluorinated ethylene propylene (FEP), which was chiefly designed to provide melt processability. In 1972 DuPont introduced another fully fluorinated polymer, perfluoroalkoxy (PEA), which is also melt processable, with better melt flow and molding properties than FEP. Although PEA has somewhat better physical and mechanical properties than FEP above 3000°F (1490°C), it lacks the physical strength of PTFE at elevated temperatures and must be reinforced or designed with thickness to compensate for its softness. The heat deflechon temperature of PFA is the lowest of all fluoropolymers. PFA is used to make tubing products. 

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