355-37-3Relevant articles and documents
Gas-phase NMR technique for studying the thermolysis of materials: Thermal decomposition of ammonium perfluorooctanoate
Krusic, Paul J.,Roe, D. Christopher
, p. 3800 - 3803 (2004)
The kinetics of the thermal decomposition of ammonium perfluorooctanoate (APFO) has been studied by high-temperature gas-phase nuclear magnetic resonance spectroscopy over the temperature range 196-234 °C. We find that APFO cleanly decomposes by first-order kinetics to give the hydrofluorocarbon 1-H-perfluoroheptane and is completely decomposed (>99%) in a matter of minutes at the upper limit of this temperature range. Based on the temperature dependence of the measured rate constants, we find that the enthalpy and entropy of activation are ΔH? = 150 ± 11 kJ mol-1 and AS? = 3 ± 23 J mol-1 deg-1. These activation parameters may be used to calculate the rate of APFO decomposition at the elevated temperatures (350-400 °C) at which fluoropolymers are processed; for example, at 350 °C the half-life for APFO is estimated to be less than 0.2 s. Our studies provide the fundamental parameters involved in the decomposition of the ammonium salt of perfluorooctanoic acid and indicate the utility of gas-phase NMR for thermolysis studies of a variety of materials that release compounds that are volatile at the temperature of decomposition and that contain an NMR-active nucleus.
Synthesis method of straight-chain perfluoroalkanes
-
Paragraph 0018; 0019; 0024, (2019/05/08)
The invention relates to a synthesis method of straight-chain perfluoroalkanes, which comprises the following steps: reaction of perfluoroalkyl iodine with alcohol solution of sodium alcohol at a certain temperature to purify 1-hydroperfluoroalkanes; reaction of 1-hydroperfluoroalkanes with fluorine gas at a certain temperature to purify straight-chain perfluoroalkanes. The synthesis method of theinvention has mild reaction conditions, high product yield, and is beneficial to cost saving. The process has low energy consumption, easy operation and is conducive to industrial production.
Thermoanalytical and preparative investigations of the decomposition of potassium perfluoroorganyl(fluoro)borate salts, K[RFBF3] (RF = perfluoroalkyl, -alkenyl, -alkynyl, and -aryl groups) and K[(RF)2BF2] (RF = C 6F5 and C6F13)
Bardin, Vadim V.,Shundrina, Inna K.,Frohn, Hermann-Josef
, p. 73 - 78 (2014/01/06)
Potassium perfluoroalkenyl(fluoro)borates, K[RFBF3], (RF = CF2C(CF3), cis-CF3CFCF, and cis-C6F13CFCF) decomposed at 208-225 C (Tmax, dTG). The K[RFBF3] salts (RF = C 3F7, C6F13, trans-CF 3CFCF, and trans-C4F9CFCF) decomposed at 273-312 C (Tmax, dTG). Both groups of salts formed volatile polyfluoroorganics and K[BF4] as solid residue. The preparative thermolysis of selected prototypical salts K[RFBF3] showed that the polyfluoroorganics consisted of a mixture of internal perfluorohexenes, C6F12, and 1-H-tridecafluorohexane, C6F13H, in case of K[C6F13BF 3], and of perfluorooctynes, C8F14, and cis-C6F13CFCFH in case of K[cis-C6F 13CFCFBF3]. The salts K[(C6F5) 2BF2] and K[RFBF3] (RF = CF3CC, CF3CFCFCC, C6F5CC, C 6F5, 2,3,5,6-C5NF4) decomposed in the temperature range 249-337 C (Tmax, dTG) and mainly resulted in non-volatile polyfluoroorganics besides K[BF4]. The reaction path of the thermolysis of perfluoroalkyl-, perfluoroalkenyl-, and perfluorophenyl(fluoro)borates is discussed and compared with that of perfluorocarboxylates.
A novel liquid plasma AOP device integrating microwaves and ultrasounds and its evaluation in defluorinating perfluorooctanoic acid in aqueous media
Horikoshi, Satoshi,Sato, Susumu,Abe, Masahiko,Serpone, Nick
experimental part, p. 938 - 942 (2012/03/08)
A simplified and energy-saving integrated device consisting of a microwave applicator and an ultrasonic homogenizer has been fabricated to generate liquid plasma in a medium possessing high dielectric factors, for example water. The microwave waveguide and the ultrasonic transducer were interconnected through a tungsten/titanium alloy stick acting both as the microwave antenna and as the horn of the ultrasonic homogenizer. Both microwaves and ultrasonic waves are simultaneously transmitted to the aqueous media through the tungsten tip of the antenna. The microwave discharge liquid plasma was easily generated in solution during ultrasonic cavitation. The simple device was evaluated by carrying out the degradation of the perfluorooctanoic acid (PFOA), a system highly recalcitrant to degradation by conventional advanced oxidation processes (AOPs). PFOA is 59% degraded in an aqueous medium after only 90 s of irradiation by the plasma. Intermediates were identified by electrospray mass spectral techniques in the negative ion mode.
