Nitroso rubbers

In general the nitroso rubbers also suffer from a poor resistanee to ionising radiation, sensitivity to degradation by organie bases, highly toxic degradation products and an exceptionally high cost. The advent of the rubbers based on perfluorofmethyl vinyl ether) considered above and of the phosphonitrilic elastomers considered below would appear to put the commercial future of these materials in extreme doubt. 

M.C. Henry et al, Synthesis, Compounding, and Properties of Nitroso Rubbers in P.R. Tarrand, ed, Fluorine Chemistry Reviews 1,... 

Trifluoronitrosomethane, CFsNO, mw 99.02 bright blue, fairly stable gas, very irritant fr p —150°, bp —84°. Can be prepd by interaction of iodo (or bromo) trifluoromethane with nitric oxide in the presence of UV light. Serves as a monomer for nitroso rubber as a military poison Refs 1) Beil 1, il05i <99 > 2) Cond-... 

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]. 

Tarrant, P. Fluorine Chem. Rev. 1 Synthesis, Compounding and Properties of Nitroso Rubber. New York Marcel Dekker 1967. 

Banks, R.E. Carson, P.A. Haszeldine, R.N. V-Fluoro compounds. VI. Preparation and some reactions of perfluoro-V,V -difluoropiperazine. Crosslinking of a nitroso rubber. J. Chem. Soc., Perkin Trans. 1 1973, (10), 1111-1114. 

They apparently reacted through the terminal nitroxide groups with fluoroalkenes, sulfur dioxide, or perfluorobutadiene to yield block copolymers of increased molecular weight(133). An unsaturated nitroso-rubber was reported when perfluorobutadiene reacted with macroradicals of perfluoropropene-1. 

Elastomeric terpolymer fi om tetrafiuoroethylene, trifluoro-nitrosomethane, and a small amount of an unsaturated monomer, e.g., nitrosoperfluorobutyric acid and nitroso or carboxy nitroso rubber... 

Carboxy nitroso rubber (CNR) n. A fluorocarbon elastomer, synthesized as a... 

Nitroso rubber n. A co-polymer of tetrafluo-roethylene and trifluoronitrosomethane. 

The rate of copolymerization of CF3 NO with C F4 in fluorocarbon-type solvents, to give the alternating copolymer known as nitroso-rubber , obeys the equation d [copolymer ]/dr = A[CF3-NOp/ [C2F4] at temperatures in the range —36 to +80 °C, with reactant ratios in the range 0.2— 5.0 and total initial monomer concentrations of 0.15—0.60 mol I". This, taken in conjunction with unsuccessful attempts to detect complex formation at... 

T. Flowers, R. N. Haszeldine, E. Henderson, A. K. Lee, and R. D. Sedgwick, J.PolymerSci.,PartA-l,PolymerChem., 1972,10, 3489. Anyone wishing to prepare nitroso-rubber samples may find it advantageous to consult Macromol. Synth., 1972, 4,147. 

Production of the nitroso-rubber (47) at the expense of the novel heterocycle (48) is favoured by use of sub-zero temperatures and condensed-phase systems. 

It seems clear, therefore, that for this particular polymer ESCA is unable to provide information on structural isomerism along the chain. (This contrasts with the situation to be described later concerning nitroso rubbers.) The same considerations apply to both polyvlny1idene fluoride and polytrif1uoroethy1ene, again the theoretical models are in excellent agreement with experiment. 

E. ESCA Studies of Structural Isomerism. Nitroso Rubbers. 

Fig. 38. Charge potential calculations on model systems for nitroso rubbers showing constancy of binding energy for CF3 carbon-ls levels.

Fig. 39. Computed shifts in C15 levels for model systems for nitroso rubbers.

Fig. 40. Deconvolution of Cis envelope for nitroso rubber involving chlorotri fluoroethy1ene.

Asbestos fiber reinforced plastic Elastomeric terpolymer from tetrafluoro-ethylene, trifluoronitrosomethane, and a small amount of nitrosoperfluorobntyric acid nitroso rubber (ANSI/ASTM) see also CNR... 

There also exists a number of speciality rubbers whose applications are either very limited or well established. These include the chlorinated polyethylenes, the epichlorhydrin rubbers, the fluorosilicones, the ethylene-vinyl acetate rubbers, the polysulphides, the nitroso rubbers and the phosphonitrile fluoroelastomers. Changes in the uses of these materials are likely to have very little impact on the usage of general purpose and major special purpose rubbers. They have also been the subject of a recent review. ... 

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