TY - JOUR A1 - Malow, Marcus A1 - Wehrstedt, Klaus-Dieter A1 - Schuurman, P. A1 - Hoeijmakers, P.M.M. T1 - Comments on 'thermal decomposition kinetic evaluation and its thermal hazards prediction of AIBN, by S. Guo, W. Wan, C. Chen and W.H. Chen' (Journal of thermal analysis and calorimetry (2013) 113:1169-1176, DOI 10.1007/s10973-013-2993-7) N2 - We read the paper by Guo et al. [1] with interest. The authors have investigated the thermal decomposition kinetics and thermal hazards of 2,2′-azobis(isobutyronitrile), AIBN, by differential scanning calorimetry (DSC) and used the Advanced Kinetics and Technology Solutions (AKTS) software to predict the thermal stability of AIBN in ton and kg scale. The main conclusion of interest is that the self-accelerating decomposition temperature (SADT) of a 50-kg standard package is 63 °C. PY - 2014 DO - https://doi.org/10.1007/s10973-014-3897-x SN - 1388-6150 SN - 1418-2874 SN - 0368-4466 SN - 1572-8943 VL - 117 IS - 3 SP - 1015 EP - 1016 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-31251 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wehrstedt, Klaus-Dieter A1 - Knorr, Annett A1 - Schuurman, P. T1 - The "Mini Closed Pressure Vessel Test (MCPVT)" as a screening or classification test for explosive properties of organic peroxides N2 - Tests according to the UN Recommendations on the Transport of Dangerous Goods for the determination of explosive properties of organic peroxides have been compared with screening criteria for explosivity based on measurements in a closed mini-autoclave (MCPVT). It will be shown that an additional screening test may be helpful but the information obtained from the UN tests are more important to characterise the specific properties of a substance under different conditions. KW - MCPVT KW - Organic peroxides KW - UN Manual of Tests and Criteria KW - Explosive properties PY - 2003 DO - https://doi.org/10.1016/j.jlp.2003.08.001 SN - 0950-4230 SN - 1873-3352 VL - 16 SP - 523 EP - 531 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-2699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steensma, M. A1 - Schuurman, P. A1 - Malow, Marcus A1 - Krause, Ulrich A1 - Wehrstedt, Klaus-Dieter T1 - Evaluation of the validity of the UN SADT H.4 test for solid organic peroxides and self-reactive substances N2 - Many self-accelerating decomposition temperatures (SADTs) of solid organic peroxides and self-reactive substances have been determined with the UN test method H.4, which is a scaled down test in a small Dewar vessel. For solid organic peroxides and solid self-reactive substances Fierz has questioned this procedure in a recent paper. Fierz concluded that the Dewar test results should not be extrapolated to beyond 8 l packages, owing to the thermal insulation value of solids. On the other hand, long term experience with the test, with a great variety of solid organic peroxides and self-reactive substances show about equal critical temperatures in the small Dewar vessel and on 50 kg scale. In the present work, we first checked, by numerical simulations, the Dewar scale versus the larger scale, in a way comparable with Fierz’ method: both scales are simulated by spheres, consisting of a number of annular layers, for the large scale the usual external heat loss term is used but for the small scale the outside heat transfer is strongly limited. The outcome of these simulations, covering a variety of physical parameters, supports the concerns expressed by Fierz. After this, we performed accurate cooling and heating experiments with solid organic peroxide in the usual Dewar vessel, provided with a large set of thermocouples. The results of these experiments showed that the simulation model for the Dewar vessel has to be changed from a spherical analogue to a short cylinder of solid material with heat exchange mainly via its top (Utop 3.5 W/(m2 K), overall heat transfer coefficient) and some heat exchange (Uside 0.29 W/(m2 K)) through its cylindrical and bottom part. With this “modified cylinder” model (being neither an infinitely long cylinder nor a slab) of the Dewar vessel, we found that the UN method H.4 enables an accurate prediction of the SADT, with small deviations of 0 ± 2.5 °C. Further, by performing a truly three-dimensional (3D) finite element calculation in FEMLAB, the new heat characteristics of the Dewar vessel as well as a 50 kg package of dilauroyl peroxide, a solid organic peroxide, were checked. The outcome was compared with the critical ambient temperatures known for various package sizes, which agreed well. KW - SADT of solids KW - Transport regulations KW - UN H.4 test (HAST) KW - Numerical simulations KW - Scale-up procedure PY - 2005 DO - https://doi.org/10.1016/j.jhazmat.2004.09.028 SN - 0304-3894 VL - 117 IS - 2-3 SP - 89 EP - 102 PB - Elsevier CY - Amsterdam AN - OPUS4-5604 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -