Trifluoronitrosomethane copolymers

The other chain scissions are accompanied by chlorine-atom transfer to the break site to form two fragments (by disproportionation) of lower molecular mass than the original polymer. Trifluoronitrosomethane copolymers are the least thermally stable. Trifluorochloroethylene copolymers occupy an intermediate position, while polyvinylidene fluoride and polytetrafluoroethylene are the most thermally stable. 

Similar phenomena may be observed in some copolymerizations. For example, tetrafluoroethylene, C2F4, and trifluoronitrosomethane, CF3NO, copolymerize spontaneously into a 1 1 copolymer,—[-CF2.CF2.0.. N(CF3).-] —.Its degradation produces, however, a pair of inert... 

A series of nitroso rubbers has been formed by reaction of trifluoronitrosomethane with fluoroalkenes [279] with tetrafluoroethene an oxazetidine and a 1 1 copolymer are obtained (Figure 8.110), the polymer being formed in preference at lower temperatures [279-281]. It is claimed that the mechanism involves electron transfer [282]. 

One of the miscellaneous fluoroolefm polymers is a copolymer of trifluoronitrosomethane and tetrafluoroethylene, an elastomer ... 

The excellent properties of fluorinated polymers have also proved useful in the case of elastomers. Alternating copolymers with a glass transition temperature of —5PC are produced by the alternating copolymerization at —20°C of tetrafluoroethylene and trifluoronitrosomethane with small amounts of 4 nitrosoperfluorobutyric acid as cross-link points. They can be vulcanized by diamines. These cold resisting elastomers are used in jet planes flying Arctic routes and for flexible rocket fuel containers. 

Alternating copolymers are obtained from the free radical copolymerization of tetrafluoroethylene with trifluoronitrosomethane, CF3NO. At higher temperatures, however, a cyclic oxazetidine is obtained ... 

The publications dealing with the mechanism of copolymerization of trifluoronitrosomethane with tetrafluoroethylene and the cross-linking of trifluoronitrosomethane-tetrafluoroethylene-hexafluorobuta-l, 3-diene copolymers with the new bis-nitroxide 0-N(CF3)CF2-CF2-N(CF3)-0-deserve further space here, on the grounds of long-standing academic and industrial interest, respectively. 

Trifluoronitrosomethane-tetrafluoroethylene copolymer may be vulcanized with a combination of triethylenetetramine and hexamethylenediamine carbamate typically, vulcanization is effected by heating at 250 C for 1 hour in the press and then 210°C in an oven for 18 hours. The mechanism of the process is unknown. 

Trifluoronitrosomethane-tetrafluoroethylene copolymer vulcanizates have outstanding resistance to chemicals, being generally superior to vinylidene fluoride-hexafluoropropylene elastomers. Some fluorinated solvents cause appreciable swelling. 

Trifluoronitrosomethane-tetrafluoroethylene copolymer has good thermal stability. The copolymer does not bum but decomposition into gaseous products begins at about 200°C. The glass transition temperature of the copolymer is -54 C and vulcanizates remain serviceable down to about -40°C. A limitation of the vulcanizates is their low tensile strength, although silica effects some reinforcement. 

The first rubbery materials prepared by Barr and Haszeldine were made by copolymerization of trifluoronitrosomethane and tetrafluoroethylene, highest yields and molecular weights being achieved at low temperatures. The copolymer was essentially of the alternating type... 

Trifluoronitrosomethane/tetrafluoroethylene copolymer (1 1) alternating infinite l,l,2-Trichloro-l,2,2- 301.6 12... 

Fluoronitrosopolymers have potential primarily as low temperature, oil-resistant elastomers but although they have attracted a good deal of interest, these materials do not appear to have progressed beyond the pilot plant stage. The most thoroughly investigated nitrosopolymer is the copolymer of trifluoronitrosomethane and tetrafluoroethylene [4]. 

Reaction of trifluoronitrosomethane with trifluoroacryloyl fluoride under forcing conditions has been shown to yield a 1 1 alternating copolymer,... 

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