Perfluoroalkoxy polymers

Fig. 2.14. The C Is XPS spectra recorded by Chin-An Chang et al. [2.68] from perfluoroalkoxy polymer (PFA). (a) before deposition, (b) deposition of copper, (c) deposition of chromium,...

Perfluoroalkoxy polymer (PFA) materials, acid resistance of, 23 785. See also PFA Perfluoroalkyl dispersant moieties,... 

Reimann, C., U. Siewers, H. Skarphagen, and D. Banks. 1999. Does bottle type and acid-washing influence trace element analyses by ICP-MS on water samples A test covering 62 elements and four bottle types High density polyethene (HDPE), polypropene (PP), fluorinated ethene propene copolymer (FEP) and perfluoroalkoxy polymer (PFA). Sci. Total Environ. 239 111-130. 

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. 

Fluoropolymers discussed include polytetrafluoro-ethylene (PTFE), perfluoroalkoxy polymer (PFA), fluorinated ethylene-propylene polymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF). 

Oxygen (0) and chlorine (Cl) are present in the chemical structure of some commercial fluoropolymers. Examples include perfluoroalkoxy polymer and polychlorotrifluoroethylene ... 

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.

Abrasion resistance is usually measured by the Taber Test procedure described by ASTM D1044. Abrasion resistance of unfilled semicrystalline polymers is linked to the degree of crystallinity that is itself related to the molecular stmcture and weight of the resin and its processing. Table 3.54 includes the results of testing two types of perfluoroalkoxy polymers, PFA and MFA, and ECTFE. Notice the large difference between wear index (weight loss by abrasion in 1000 cycles) of ECTFE which is a partially... 

The melting of a semierystalline or crystalline pol mier exhibits itself as an endothermic peak. The peak temperature is correspondent to the actual melting point of the pol mier. As in DSC, the area under the peak is proportional to the crystalline fraction of the sample. Mixtures of polymers can be characterized by DTA because the melting points of individual pol miers are, for the most part, unaffected by the mixture. Similar pol miers, such as high and low density, are distinguishable by DTA while infrared spectroscopy would not be able to easily resolve such subtle differences. Figure 10.29 shows a thermogram of a mixture of polytetrafluoroethylene (PTFE) and perfluoroalkoxy polymer (PFA). 

Many different gases and plasma operating parameters are used to surface treat different materials. Studies have been performed on the effect of these different plasmas on various polymers. It has been found that, for best results, different polymers may require different plasma treatment. In some cases it has been found that a plasma which gives excellent resixlts on one polymer may give very poor results on a similar polymer. For example, the best process for perfluoroalkoxy polymer (PFA) gives poor bonding to fluorinated ethylene-propylene polymer (FEP). 

Figure 26. The C 1 s XPS spectra recorded by Chin-An CHANG et al. 6I) from perfluoroalkoxy polymer (PFA) a) Before deposition b) Deposition of copper c) Deposition...

Polytetrafluoroethylene Perfluoroalkoxy polymer Fluorinated ethylene-propylene copolymer Ethylene-tetrafluoroethylene copolymer Polyvinylidene fluoride Ethylene-chlorotrifluoroethylene copolymer... 

For example, perfluoroalkoxy polymer (PEA) is a copolymer of IFE and perfluoro kylvinylether that contains oxygen. R is a perfluoroalkyl group of C, toC. ... 

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