Polymers perfluoroalkoxy resin

Perfluoroalkoxy resin (PFA) n. A class of melt-processable fluoroplastics in which perfluoroalkyl side chains are cormected to the fluorocarbon backbone of the polymer through flexible oxygen linkages. 

PFA polymers are fully fluorinated and melt processible. They have chemical resistance and thermal stability comparable to polytetrafluoroethylene (PTFE). Melt viscosity of PFA is over one million times lower than PTFE. Perfluoroalkoxy resins are in general copolymers of tetrafiuoroethylene with one or more of perfluoroalkyl vinyl ether comonomers. Commercial examples of the latter include perfluoromethyl vinyl ether (PMVE), perfluoroethyl vinyl ether (PEVE), and perfluoropropyl vinyl ether (PPVE). PFA resins are specified by ASTM Method D3307, which also provides procedures or references to other ASTM methods for the measurement of resin properties. Commercial PFA resins offered by major manufacturers have been listed in Tables 6.1 through 6.7. 

Copolymerizahon of TFE and perfluoro(propyl vinyl ether) (PPVE) yields melt-processable, linear polymers known as perfluoroalkoxy (PFA) resins of the following general structure... 

The need for highly fluorinated thermoplastic polymers that, unlike PTFE, could be fabricated by conventional melt-processing methods led to the development of a group of resins that are copolymers of tetrafluoroethylene (TFE) with other perfluo-rinated monomers. Commercially, the copolymer of TFE and hexafluoropropylene (HEP) is commonly known as fluorinated ethylene propylene (FEP). Copolymerization of TEE with perfluoropropylvinyl ether (PPVE) leads to perfluoroalkoxy (PEA) resins, and copolymerization of TFE with perfluoromethylvinyl ether (PMVE) produces methylfluoroalkoxy (MEA) resins. 

Fluoroplastics are a class of paraffinic polymers that have some or all of the hydrogen replaced by fluorine. These include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP) copolymer, perfluoroalkoxy (PFA) resin, polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoro-ethylene (ECTFE) copolymer, ethylene-tetrafluoroethylene (ETFE) copolymer, polyvinylidene fluoride (PVDF), and polyvinylfluoride (PVF) [186],... 

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... 

Hyflon PFA perfluoroalkoxy fluorocarbon resins design and processing guide. Solvay Specialty Polymers 2012. 

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