Trifluoronitrosomethane/tetrafluoroethylene copolymer: Degradation by heat and by radiation

Thermal degradation of trifluoronitrosomethane/tetrafluoroethylene copolymer yields COF2 and CF3NCF2 as gaseous decomposition products. The copolymer weight loss appears first order in copolymer. The activation energy is 58 kcal./mole, and the first‐order rate constant is approximately k1 (min.−1) = 3.1 ′ 1021 exp {‐29,047/T} determined in the 250–265°C. range. A rather large weight fraction of low molecular weight species exists in some nonfractionated copolymer samples leading to rapid initial weight losses upon heating. Thermogravimetric and differential thermal analyses were used to observe a thermal runaway decomposition at temperatures above 270°C. Gamma radiations from spent atomic fuel elements produce random scissions in the copolymer chains followed by COF2 and CF3NCF2 evolution. At 23°C. the total energy absorption per primary chain scission is Ed = 44 e.v./scission. For each chain scission an average of approximately 5.3CF2N(CF3)OCF2 units decompose to COF2 and CF3NCF2. In systems containing these product gases at appreciable pressure an adduct, (CF3)2NCOF, is produced. Ultraviolet light of 2537 A. wavelength photolyzes the copolymer producing random chain scissions and the gases COF2 and CF3NCF2. The quantum yield for primary random chain scission at 23°C. is ϕd = 0.91 × 10−3 scissions/absorbed photon; the equivalent total energy absorption per event is Ed = 5400 e.v./scission. An average of approximately 3.6 CF2N(CF3)OCF2 units decompose to COF2 and CF3NCF2 for each chain scission.