Effect Of Accelerated Aging On The Safety Of Vehicle Emulsion Matrix

In order to study the safety of emulsion matrix under the condition of long distance transportation, emulsion matrix samples were prepared respectively by the temperature shock aging test and the vibration aging test, which were evaluated by measuring the amount of NH4NO3 precipitated, the conductivity and viscosity of aged emulsion matrix samples. The result indicates that the temperature shock aging test is more effective to accelerate aging of emulsion matrix. Based on the temperature shock aging test, shock sensitivity of aged emulsion matrix samples were tested by the ANE gap test, the sensitivity of aged emulsion matrix samples substances to intense heat with varied confinement were tested by the Koenen test, relative thermal stability and thermal decomposition were determined by differential scanning calorimetry (DSC) and Vented pipe test.In DSC thermal analysis test,5,9,11,14 and 20 accelerated aging cycles, the onset temperature of samples were decreased from 279.10℃ to 273.51℃,271.93℃,266.31℃, 259.49c℃ and 246.95℃ respectively. The results indicate that the thermal stability of emulsion matrix was decreased with the increased of accelerated aging cycles. In the Vented pipe test, the samples after 7 and 20 accelerated aging cycles, the time reaches to the maximum temperature was decreased from 1340s to 1020s and 700s. The results indicate that the thermal decomposition rate of emulsion matrix rises obviously with the increase of aging cycles. In the ANE gap test, verification boards of the sample after 0,7 accelerated aging cycles, the witness plates were not broken down by shock waves, while the witness plates of sample that after 20 accelerated aging cycles wholly broken down by shock waves. The results of ANE gap test show that with the increase of the aging cycles, emulsion matrix is more sensitive to the shock wave. In the Koenen test, the test tubes of the sample after 0,7 accelerated aging cycles were unchanged, while the test tube of the sample after 20 accelerated aging cycles was fragmented. It indicates that with the increase of the aging cycles, emulsion matrix is more sensitive to the effect of intense heat under confinement. According to the results of the above experiments, it shows that the impact of temperature has an important influence on the thermal stability and explosive characteristics of emulsion matrix.