Study of the Basic Kinetics of Decomposition of MMH and MHF and the Effects of Impurities on Their Stability.

摘要

Monomethyl hydrazine (MMH) stability in hexadecane solution is sensitive to the presence of transition metal salts. In experiments at 200 in which the ratio of MMH to metal was 90:1, MMH was completely destroyed within five minutes when in the presence of Ni(II), Fe(II), and Fe(III). Cu(II), on the other hand, brought about decomposition at a considerably slower rate--72 percent destruction of MMH in 72 hours. The product distributions in these experiments are dependent to some extent upon the metal salts present. The degree of MMH decomposition in an experiment with Ni(II) was independent of the presence of oxygen. Thus, there appears to be no synergistic effect operating on MMH destruction when MMH is in the presence of both O2 and a transition metal salt. The surfaces of the metal alloys, aluminums 6061, 1100, 2014; stainless steels 347,321, and 17-7PH; and inconel X-750, showed no effect on the decomposition of neat MMH in runs at 100C for 7 days. The acid salts MMH.HNO3 and MMH.HCl were studied in their respective aqueous acid solutions at 72.8C. The hydrochloride salt was perfectly stable over a period of 346 hours. In that period, on the other hand, the hydronitrate salt decomposed to the extent of 73 percent. The products included N2, CH3NH2, NH3, and C2H6. The presence of both N2 and C2H6 suggests the presence of methyl radicals which could result from the formation of CH3N=NH. (Author)