Perfluoroalkoxy teflon

Somewhat between PTFE and PFA materials is the product Hostaflon TFM, which is a copolymer of TFE and a small amount of the perfluoro(propyl vinyl ether). It has improved impact strength and weldability and has been promoted as a suitable material for forming into bottles. Yet another TFE-perfluoroalkoxy copolymer was introduced by Du Pont in 1979 as Teflon EPE. This material had a somewhat lower melting point (295 °C) than the more common PFA fluoropolymers but it is no longer marketed. 

PA PCP PCR PFA PGB PHA PID PLC PMACWA PMD POTW ppm PRH PRR psi psig PTFE PVDF PWS picric acid pentachlorophenol propellant collection reactor perfluoroalkoxy product gas burner preliminary hazards analysis proportional integral differential controller programmable logic control Program Manager for Assembled Chemical Weapons Assessment projectile mortar demilitarization (machine) publicly owned treatment works parts per million projectile rotary hydrolyzer propellant removal room pounds per square inch pounds per square inch gauge polytetrafluoroethylene (Teflon) polyvinylidene fluoride projectile washout system... 

Figure 3.9. In the oven cavity is a carousel (turntable or rotor) that can hold multiple extraction vessels. The carousel rotates 360° during extraction so that multiple samples can be processed simultaneously. The vessels and the caps are constructed of chemically inert and microwave transparent materials such as TFM (tetrafluoromethoxyl polymer) or polyetherimide. The inner liners and cover are made of Teflon PFA (perfluoroalkoxy). The vessels can hold at least 200 psi of pressure. Under elevated pressures, the temperature in the vessel is higher than the solvent s boiling point (see Table 3.11), and this enhances extraction efficiency. However, the high pressure and temperature may pose safety hazards. Moreover, the vessels need to be cooled down and depressurized after extraction.

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. 

Onuki et al. have screened a number of materials in an acid mixture of H2SO4 (50 wt%) and HI (0.1 wt%) at temperatures up to 120°C (table 4.7). This simulates the composition of the upper liquid phase. They found Ta, Zr, Pb, and quartz glass to be corrosion resistant in this acid complex, whereas common construction material such as stainless steel and Hastelloy did not possess acceptable corrosion rates. PFA (Teflon) also showed satisfactory corrosion performance, but I2 absorption by perfluoroalkoxy or PFA has been observed, which raises questions about its longterm viability. 

Storage of water samples to detect trace metals is normally carried out in plastic containers fluorinated plastic materials i.e.. Teflon, fluorinated ethylene propylene (FEP), perfluoroalkoxy polymers (PFA) or polyethylene are used because if opportunely treated and conditioned they guarantee contamination-free samples. However, FEP or Teflon bottles are preferable to those made of polyethylene when speciation studies are carried out. In fact, polyethylene over long periods of storage can release plasticizers (above all phthalates or amines), which behave as ligands and modify the complexation equilibria of the solution. When Hg is to be determined plastic materials must be avoided because they are permeable to gases and vapours glass or quartz are therefore used. 

Table 1.1. Gas Permeability of Carbon Dioxide, Nitrogen, and Oxygen through DuPont Teflon PFA Perfluoroalkoxy Film...

General Description Perfluoroalkoxy (PFA) films have extremely high temperature resistance. DuPont high-performance material Teflon PFA resin is available in pellet or powder,... 

Teflon PFA Fluorocarbon, perfluoroalkoxy resin, PFA E. I. du Pont de Nemours... 

Perfluoroalkoxy (PFA) is another effective alternative to PTFE Teflon. However, being more expensive than FEP, but withstanding higher temperatures and containing fewer impurities, is especially usefid for delicate applications. 

Fluorinated copolymers perfluoroalkoxy (PFA) Teflon AF fluorinated ethylene propylene (FEP)... 

Polytetrafluoroethylene (PTFE) and its copolymers fluoroethylenepropylene (FEP), perfluoroalkoxy (PFA), and amorphous PTFE, a perfluorinated dioxole (Teflon AF), are the best electret materials for storing negative charges due to the large electronegativity of the F atom and the highly symmetrical CF2 group with its... 

Teflon PFA 340 Copolymer of tetra-fluoroethylene and a perfluoroalkoxy monomer (PFA) general purpose, medium viscosity, melt extrusion resin. 

Polymers should be tested for extractables before use. The amount of extractable material is determined by the formulation of the polymer mix. Molded plastics often have a high plasticizer content to make them more fluid for molding. These low molecular weight plasticizers migrate to and contaminate the surface. In semiconductor processing, a relatively inert fluoropolymer (perfluoroalkoxy (PFA), e.g. Teflon or Neoflon ) is often used for containers and holders but they can hberate corrosive fluorine compounds. Special treatments are used to reduce the extractable fluoride compounds from these materials. Many polymers can absorb water vapor and corrosive gases from the environment. 

Perfluoroalkoxy Perfluoroalkoxy alkane PFA Teflon, Neoflon, Hyflon... 

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