Thermal oxidative degradation reactions of linear perfluoroalkyl ethers
Thermal oxidative degradation reactions of linear perfluoroalkyl ethers
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直链全氟烷基醚的热氧化降解反应
DOI：
10.1021/i300010a002
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
R. Kratzer
中科院分区：
文献类型：
--
作者：
W. R. Jones;K. J. L. Paclorek;T. Ito;R. Kratzer
项目经理，William R. jones， nasa刘易斯研究中心，克利夫兰，Otf 44L3516 absn4l该合同的目的是研究热降解和热氧化降解的机制[c] [formblln Z和he×afluoropropene氧化物衍生流体，以及合金和添加剂的影响]，[c] +, [c] +, [c] +, [c] +。目前还没有确定氟化氢的热氧化不稳定性的性质。确定这种行为与氢端基或过氧键无关。这些流体在高温和氧化气氛下的降解速率与表面/体积比有关。一旦达到极限比率，似乎就会达到稳定的比率。根据元素分析和耗氧数据，- cf2ocf2cf2o - ‘不是- cf2cf2o - ’是目前的主要排列之一。M-50和TI的动作。4Mn)合金在PombllnZ流体中比在六氟丙烯氧化物衍生材料中观察到的更为剧烈。抗氧化/防腐添加剂的有效性；在316℃时，P-3和磷-s- trazine在有金属合金存在的情况下是非常有限的；在28B℃时，添加剂几乎完全阻止了流体降解。磷-s-三唑啉的效果至少是P-3化合物的两倍；它也更好地保护了优惠券。TI{4AI, 4,Mn)合金主要通过链式scjsslon过程降解流体，而M-S0合金的这种降解程度要小得多。用核磁共振谱法证实了Krytox MLO-YL-6液中存在一定比例的端氢链。当流体暴露于343°C的氧气中时，这些都被消除了，而在316°C的氧气中，铝金属似乎没有促进链剪：观察到纯钛金属的稳定但低的降解率。
Project Manager, William R. JonesNASA Lewis Research CenterCLeveland, Otf 44L3516 Absn4clThe objective of this contract was to Investigate the mechanisms operative tn thermal and thermaloxidative degradation c)[ Fomblln Z and he×afluoropropene oxide derived fluids and the e{[ect of alloysand additives upon thest+ pr,_cess+;s.'I'h+. nature r_[ arranq(:ments rttsponslbJe for the tnherez_t thermal oxidative instability of the Fon)blJn Zt'luLds has not been establh;hed. Lt was determined that this behavior was not associated withhydruqen end-groups or peroxy linkages. The degradation rate of these fluids at elevated temperaturesLn oxidizing atmospheres was [ound to be dependent on the surface/volume ratio. Once a limitingratio was reached, a steady rate appeared to be attained. Based on elemental analysis and oxygenconsumption data, -CF 2 OCF 2 CF 2 O- ' not -CF 2 CF 2 O- ' Is one o[ the major arrangements present. Theaction ot" the M-50 and TI(4A.I. 4Mn) alloys was [ound to be much more drastic In the case of PombllnZ fluids than that observed for the hexafluoropropene oxide derived materials. The e[fecttveness ofantloxldation/anticorroston additives; P-3 and phospha-s-trlazine, In the presence of metal alloys'was very Limited at 316°C: at 28B°C the additives arrested almost completely the fluid degradation.The phospha-s-triazlne appeared to be at Least twice as effective as the P-3 compound; It alsoprotected the coupon better. The TI{4AI, 4,Mn) alloy degraded the fluid mainly by chain scJsslonprocesses: this took place to a much lesser degree with M-S0.The presence of a certain proportion of hydrogen-terminated chains In Krytox MLO-YL-6 fluid wasverified by NMR spectroscopy. These were eliminated on exposure of the fluid to oxygen at 343°C.]'n oxygen at 316°C, aluminum metal did not seem to promote chain scissJons: a steady but low rateof degradation was observed for pure titanium metal.