Perfluoropropyl vinyl ether

Properties. Properties of perfluoropropyl vinyl ether [1623-05-8] (PPVE), a colorless, odorless Hquid (mol wt 266) are shown in Table 1. Perfluoropropyl vinyl ether is an extremely flammable Hquid and bums with a colorless flame. It is significantly less toxic than hexafluoropropylene the average lethal concentration (ALC) is 50,000 ppm (10). 

The inability to process PTFE by conventional thermoplastics techniques has nevertheless led to an extensive search for a melt-processable polymer but with similar chemical, electrical, non-stick and low-friction properties. This has resulted in several useful materials being marketed, including tetrafluoro-ethylene-hexafluoropropylene copolymer, poly(vinylidene fluoride) (Figure 13.1(d)), and, most promisingly, the copolymer of tetrafluoroethylene and perfluoropropyl vinyl ether. Other fluorine-containing plastics include poly(vinyl fluoride) and polymers and copolymers based on CTFE. 

Perfluoropropyl vinyl ether (PPVE), properties of, 18 330 Perfluorosulfonate ionomers, 14 475... 

Tetrafluoroethylene-(TFE)-perfluoropropyl vinyl ether copolymers, 7 641 Tetrafluoroethylene-perfluorovinyl ether, 48 329-339. See also Teflon PFA copolymerization of, 48 330—331 Tetrafluoroethylene-perfluorodioxole copolymers, 48 339—342. See also Teflon AF copolymers applications of, 48 342 economic aspects of, 48 341—342 health and safety factors related to, 48 342 monomer preparation, 48 339 synthesis of, 48 339-340 Tetrafluoroethylene (TFE) copolymerization with... 

Additions of elemental halogens to unsaturated compounds are among the most common preparations of halogenated fluoroorganics. The transformations are usually fairly clean and proceed in good yields. Besides the numerous examples of halogen addition tofluoroalkenes and fluoroalkyl-substituted alkenes, additions to perfluoropropyl vinyl ether [2] and fluorinated styrenes [5, 4] have been reported. Both ionic and free-radical processes occur (equations 1 and 2)... 

In diglyme or 2-hydroxyethanol, perfluoropropyl vinyl ether [355 R = F(CF2)30] reacts with sodium carbonate to give (356 same R) which on heating at 113-132 °C gives rise to (357 same R) and (358 same R) via parallel mechanisms.319... 

PPVE — Perfluoropropyl vinyl ether monomer used for the production of PFA. 

As with the higher impact resistance achievable with polystyrene when styrene is copolymerized with a rubber, the melt-forming temperatures of PTFE resin may be conveniently lowered by copolymerization of tetrafluoroethylene with low ratios of perfluoropropyl vinyl ether (boiling point, 36°C). The polymerization may be conducted in either an aqueous medium or in an organic solvent (Eq. 23.8). 

PFA is a copolymer of TFE and a perfluoroalkyl vinyl ether, such as perfluoropropyl vinyl ether PPVE. Copolymerization of perfluoroalkylvinyl ethers with tetrafluoroethylene can be done in a halogenated sol-... 

Commercially, PFA is polymerized by free-radical polymerization mechanism usually in an aqueous media via addition polymerization of TFE and perfluoropropyl vinyl ether. The initiator for the polymerization is usually water-soluble peroxide, such as ammonium persulfate. Chain transfer agents such methanol, acetone and others are used to control the molecular weight of the resin. Generally, the polymerization regime resembles that used to produce PTFE by emulsion polymerization. Polymerization temperature and pressure usually range from 15 to 95°C and 0.5 to 3.5 MPa. 

Copolymers of tetrafluoroethylene and ethylene are highly crystalline and fragile at elevated temperatures and are modified by a third monomer. Production of ETFE terpolymers having improved high temperature mechanical (especially tensile) properties has been demonstrated. They comprise of 40-60 mol% ethylene, 40-60 mol% tetrafluoroethylene, and a small amount of a polymerizable vinyl termonomer, such as perfluoroisobutylene, perfluoropropyl vinyl ether, and hexafluoropropylene. 

Figure 5. Variation of small-angle Bragg spacing with comonomer molar ratio 0, unhydrolyzed polymer (tetrafluoroethylene/perfluoropropyl vinyl ether) fluorocarbon resin.

Analysis of a liner sample by FTIR confirmed that the tube was made of PTFE. A peak was detected for perfluoropropyl vinyl ether (PPVE) indicating that PTFE was modified by a small amount of PPVE. No differences were found between the failure and normal areas after analysis by optical and scanning electron microscopy and EDX except for the small crack in the PTFE tube at the failure point. EDX detected similar amounts of F and C in both areas, as expected. 

Modifier - Generally a modifier refers to an additive which alters the properties of the host system. In the case of PTFE (polytetrafluoroethylene), a modifier is a comonomer which modifies the properties of PTFE and is present at low concentration (<1%). An example is perfluoropropyl vinyl ether. 

Scheme 2 Chemical structures of a poly(perfluorosulfonic acid) b sulfonated polystyrene (SPS) c sulfonated polystyrene-fc-(ethylene-co-butylene)-fc-sulfonated polystyrene (SSEBS) d sulfonated polystyrene-fc-(isobutylene)-fc-sulfonated polystyrene (SSIBS) e poly(ethylene-co-tetrafluoroethylene)-g-polystyrene sulfonic acid (ETFE-g-PSSA) f poly(vinylidene fluoride)-g-polystyrene sulfonic acid (PVDF-g-PSSA) g poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether)-g-polystyrene sulfonic acid (FEP-g-PSSA) h sulfonated trifluorostyrene-trifluorostyrene copolymer (PTFSSA)...

The first of these copolymers was with tetrafluoroethylene and hexa-fluoropropylene (FEP). Later, a copolymer of tetrafluoroethylene with small amounts of perfluoropropyl vinyl ether was made, and finally, an alternating copolymer of tetrafluoroethylene and ethylene was developed. All of these copolymers have similar properties to PTFE, but in contrast to the latter, they can be melt processed (see also Section 36.4). 

Tetrafluoroethylene-co-perfluoropropyl vinyl ether WAXD SEM n had 98 mol% tetrafluoroethylene do et al. (2000)... 

Tetrafluoroethylene-perfluoropropyl vinyl ether copolymers [26655-00-5] are made in aqueous (1,2) or nonaqueous media (3). In aqueous copolymerizations water-soluble initiators and a perfluorinated emulsifying agent are used. Molecular weight and molecular weight distribution are controlled by a chain-transfer agent. Sometimes a second phase is added to the reaction medium to improve the distribution of the vinyl ether in the polymer (13) a buffer is also added. In nonaqueous copolymerization, fluorinated acyl peroxides are used as initiators that are soluble in the medium (14) a chain-transfer agent may be added for molecular weight control. 

Perfluoro-2-inethylene-l,3-dioxolane monomers copolymerizes with various commercially available fluorovinyl monomers, too. Perfluoro-3-methylene-2,4-dioxabicyclo [3,3,0] octane (Figure 16.5F) was copolymerized with chlorotrifluo-roethylene (CTFE), perfluoropropyl vinyl ether, perfluoromethyl vinyl ether, and vinylidene fluoride [23] by a free radical initiator such as perfluorodibenzoylperox-ide or tert-butyl peroxypivalate in bulk or in solution, respectively (see Figure 16.9). 

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