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- Author or Editor: Zhi Ming Zhou x
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Abstract
The thermal decomposition behavior of 3,4,5-triamino-1,2,4-triazole dinitramide was measured using a C-500 type Calvet microcalorimeter at four different temperatures under atmospheric pressure. The apparent activation energy and pre-exponential factor of the exothermic decomposition reaction are 165.57 kJ mol−1 and 1018.04s−1, respectively. The critical temperature of thermal explosion is 431.71 K. The entropy of activation (ΔS ≠), enthalpy of activation (ΔH ≠), and free energy of activation (ΔG ≠) are 97.19 J mol−1K−1, 161.90 kJ mol−1, and 118.98 kJ mol−1, respectively. The self-accelerating decomposition temperature (T SADT) is 422.28 K. The specific heat capacity of 3,4,5-triamino-1,2,4-triazole dinitramide was determined with a micro-DSC method and a theoretical calculation method. Specific heat capacity (J g−1K−1) equation is C p = 0.252 + 3.131 × 10−3 T (283.1 K < T < 353.2 K). The molar heat capacity of 3,4,5-triamino-1,2,4-triazole dinitramide is 264.52 J mol−1 K−1 at 298.15 K. The adiabatic time-to-explosion of 3,4,5-triamino-1,2,4-triazole dinitramide is calculated to be a certain value between 123.36 and 128.56 s.
Abstract
The enthalpies of dissolution for di(N,N-di(2,4,6,-trinitrophenyl)amino)-ethylenediamine (DTAED) in dimethyl sulfoxide (DMSO) and N-methyl pyrrolidone (NMP) were measured using a RD496-2000 Calvet microcalorimeter at 298.15 K. Empirical formulae for the calculation of the enthalpies of dissolution (Δdiss
H) were obtained from the experimental data of the dissolution processes of DTAED in DMSO and NMP. The linear relationships between the rate (k) and the amount of substance (a) were found. The corresponding kinetic equations describing the two dissolution processes were 
for the dissolution of DTAED in DMSO, and 
for the dissolution of DTAED in NMP, respectively.
Abstract
The thermal decomposition behaviors of 1,2,3-triazole nitrate were studied using a Calvet Microcalorimeter at four different heating rates. Its apparent activation energy and pre-exponential factor of exothermic decomposition reaction are 133.77 kJ mol−1 and 1014.58 s−1, respectively. The critical temperature of thermal explosion is 374.97 K. The entropy of activation (ΔS
≠), the enthalpy of activation (ΔH
≠), and the free energy of activation (ΔG
≠) of the decomposition reaction are 23.88 J mol−1 K−1, 130.62 kJ mol−1, and 121.55 kJ mol−1, respectively. The self-accelerating decomposition temperature (T
SADT) is 368.65 K. The specific heat capacity was determined by a Micro-DSC method and a theoretical calculation method. Specific heat capacity equation is 
(283.1 K < T < 353.2 K). The adiabatic time-to-explosion is calculated to be a certain value between 98.82 and 100.00 s. The critical temperature of hot-spot initiation is 637.14 K, and the characteristic drop height of impact sensitivity (H
50) is 9.16 cm.
The present study was designed to investigate the cryotolerance of in vitro fertilised (IVF) mouse embryos at various preimplantation developmental stages. IVF mouse embryos were vitrified by the open-pulled straw (OPS) method. After warming, embryos were morphologically evaluated and assessed by their development to blastocysts, hatched blastocysts or term. The results showed that a high proportion (93.3–100.0%) of vitrified embryos at all developmental stages were morphologically normal after recovery. The developmental rate of vitrified 1-cell embryos to blastocyst (40.0%) or hatched blastocyst (32.7%) or term (9.3%) was significantly lower than that from other stages (P < 0.05). Vitrified embryos from 2-cell to early blastocyst stage showed similar blastocyst (71.8–89.5%) and hatched blastocyst rates (61.1–69.6%) and could develop to term without a significant loss of survival compared with those of fresh embryos (P > 0.05). Vitrified 2-cell embryos showed the highest survival rate in vivo (50.6%, 88/174), compared with that from other stages (9.3–30.5%, P < 0.05). The data demonstrate that the OPS method is suitable for the cryopreservation of IVF mouse embryos from 2-cell stage to early blastocyst stage without a significant loss of survival. Embryos at the 2-cell stage had the best tolerance for cryopreservation in the present study.
