Terpolymers of tetrafluoroethylene

In the mid-1980s Hoechst introduced a related material, Hostaflon TFB, a terpolymer of tetrafluoroethylene, hexafluoropropene and vinylidene fluoride. 

In attempts to further improve the stability of fluorine-containing elastomers Du Pont developed a polymer with no C—H groups. This material is a terpolymer of tetrafluoroethylene, perfluoro(methyl vinyl ether) and, in small amounts, a cure site monomer of undisclosed composition. Marketed as Kalrez in 1975 the polymer withstands air oxidation up to 290-315°C and has an extremely low volume swell in a wide range of solvents, properties unmatched by any other commercial fluoroelastomer. This rubber is, however, very expensive, about 20 times the cost of the FKM rubbers and quoted at 1500/kg in 1990, and production is only of the order of 1 t.p.a. In 1992 Du Pont offered a material costing about 75% as much as Kalrez and marketed as Zalak. Structurally, it differs mainly from Kalrez in the choice of cure-site monomer. 

In 1991 MMM announced Fluorel II, a terpolymer of tetrafluoroethylene, vinylidene fluoride and propylene. As might be expected from the structure, this is intermediate between FKM and Aflas, having better resistance to many newer automotive oils, lubricants and transmission fluids than the former but better heat resistance than the latter. 

Terpolymer of Tetrafluoroethylene, Hexafluoropropylene, and Vinylidene Fluoride (THV Fluoroplastic)... 

Chemically, THV Fluoroplastic (hereafter referred to as THV) is a terpolymer of tetrafluoroethylene (TFE), hexafluoropropylene (HFP), and vinylidene fluoride (VDF) produced by emulsion polymerization. The resulting dispersion is either processed into powders and pellets or concentrated with emulsifier and supplied in that form to the market.91 Currently, the manufacturer is Dyneon LLC and there are essentially nine commercial grades (five dry and four aqueous dispersions) available that differ in the monomer ratios and consequently in melting points, chemical resistance, and flexibility. 

Daikin Industries DuPont Fluoroproducts Note PTFE, polytetrafluoroethylene CTFE, chlorotriflua oethylene EFEP, per-fluorinated copolymer of ethylene and propylene ETFE, copolymer of ethylene tetrafluoroethylene PFPE, perfluorinated polyether EClFE, copolymer of ethylene and chlorotrifluoroethylene HIE, ter-polymer of hexafluoropropylene, tetrafluoroethylene, and ethylene MFA, copolymer of perfluoromethyMnylether and tetrafluoroethylene PEA, copolymer of perfluoropropylvinylether and tetrafluoroethylene FEP, fluorinated ethylene-propylene copolymer PVDF, poly(vinylidene fluoride) THV, terpolymer of tetrafluoroethylene, hexafluoroprqjylene, and vinyUdene fluoride PCTFE, poly(chlorotriflua oethylene). 

THV (fluoroplastic) A terpolymer of tetrafluoroethylene (TFE), hexafluoropro-pylene (HFP), and vinylidene fluoride (VDF). 

Application of diallyl terephthalate as an accelerator for curing fluorinated polymers such as a terpolymer of tetrafluoroethylene, vinylidene fluoride, and perfluoropropylene [123]. 

Terpolymers of tetrafluoroethylene, perfluoromethyl vinyl ether, and small amounts of a cross-linking termonomer, such as, for example, perfluoro(4-cyanobutyl vinyl ether), are free radically copolymerized in emulsion. Vulcanization occurs by cyclotrimerization of the cyano groups to s-triazine rings. The elastomer has a glass transition temperature of —12 C and a brittle temperature of —39° C. It is very resistant to weathering and possesses a good low-temperature flexibility. 

THV -Fluoroplastic Terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride (processing at 130 °C) 3M... 

Fluoroelastomers can be polymerized with copolymers and terpolymers of tetrafluoroethylene, hexafluoroethylene, and vinylidene fluoride. The fluorine content largely determines chemical resistance and Tg, which increases with increasing fluorine content. Low-temperature flexibility decreases with increasing fluorine content. The fluorine content is typically 57% wt. ... 

Applications for FEF include chemical process pipe linings, wire and cable, and solar collector glazing. A material similar to FEF, Hostaflaon TFB (Hoechst) is a terpolymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride. 

Table 5.6. Effect of Perfluorovinylether on the Properties of Terpolymers of Tetrafluoroethylene °i...

Hartwimmer and Kuhls l reported synthesis of non-elastomeric terpolymers of tetrafluoroethylene (TFE) in aqueous medium. These polymers were comprised of perfluoroalkylvinyl ethers (PAVE) and hexafluoropropylene (HFP) in addition to TFE. The authors reported increased PAVE, such as perfluoro-propylvinyl ether (PPVE), incorporation due to the presence of HFP. Additional PAVE suppresses the melting point of the copolymer without a loss of mechanical properties. 

Table 5.8. Effect of Hexafluoropropylene on Perfluoropropylvinyl Ether Incorporation in Terpolymers of Tetrafluoroethylene ...

Table 5.10. Mechanical Properties of Terpolymers of Tetrafluoroethylene (at Room Temperature) After Thermal Aging...

A terpolymer of tetrafluoroethylene, hexafluoro-propylene, and perfluoropropylvinyl ether was re-ported " ] to have superior stress crack resistance than TFE/HFP copolymer. The terpolymer in this development was prepared by the nonaqueous polymerization process described in US Patent numbers 3,528,954 and 4,029,868.In this procedure a halogenated solvent, in which perfluoropropylvinyl ether and a chain transfer agent had been dissolved, acted as the polymerization medium. Methanol was a common example of an effective chain transfer agent. Polymerization was carried out in a stainless steel pressure vessel. The polymer contained 0.2-2% perfluoropropylvinyl ether and 9-17% hexafluoropropylene. 

A terpolymer of tetrafluoroethylene (60 mole %), perfluoro(methyl vinyl ether) (VII) and a perfluorinated monomer with a reactive site is also commercially available. The material may be cross-linked to give an elastomer which has very low volume swell in a wide range of solvents and which withstands air oxidation up to 315°C. 

Poly(tetrafluoroethylene) (PTFE), which is also known as Teflon in trade and is a solid at room temperature, has a dielectric constant (5) in the range of 2.00-2.08 whfle its monomer, tetrafluoroethylene, is a gas at room temperature. Poly(tetrafluoroethylene) is exceptional chemiodly inert, has eireellent electrical properties, has outstanding stability, and retains mechanical properties at high temperatiures. The problem with po tetrafluoroethylene) is that it is not processable. A family of commercial polymeric materials known as Teflon AF in trade is believed to be a terpolymer of tetrafluoroethylene 9, perfluoroprofy-lene and 2,2-bis(trifluoromethyl)-4,5-difluoro-13-dioxole 8(a derivative of hex-afluoroacetone) is reported to have a dielectric constant in the range of 1.89-1.93. It is reported to be more processable than poly(tetrafiuoroethylene) (d). 

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