THERMOKINETICS Software (TK)

Evaluation of Kinetic Parameters
from Conventional Thermoanalytical Data

Technical comments

Kinetic analysis of solids of the quasi-autocatalytic decomposition type: SADT determination of low-temperature polymorph of AIBN

Simulations of SADT values based on the heat balance of the system are presented for azobisisobutyronitrile (AIBN). These simulations used kinetic parameters obtained from heat flow calorimetry experiments performed at temperatures in the stability range of low-temperature (L-T) polymorph of AIBN. Thermal Activity Monitor (TAM) data were collected in the range of 55-70 °C. The simulated SADT value for L-T AIBN amounts to 46 °C. This is very similar to the computed results obtained in the BAM project for the high-temperature (H-T) form of AIBN which amounts to 47 °C and is also in full agreement with the large scale experimentally found SADT of AIBN (47 °C) …

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Thermal decomposition of AIBN, Part B: Simulation of SADT value based on DSC results and large scale tests according to conventional and new kinetic merging approach

The paper presents the results of the common project performed with the Federal Institute for Materials Research and Testing, Berlin, Germany (BAM) concerning the comparison of the experimental results with simulations based on the application of the kinetic-based method and heat balance of the system for the determination of the self accelerating decomposition temperature (SADT). The substantial potential of the kinetic-based method is illustrated by the results of the simulation of SADT of azobisisobutyronitrile (AIBN) …

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Determination of Thermal Hazard from DSC measurements. Investigation of Self-Accelerating Decomposition Temperature (SADT) of AIBN

The method of determination of the thermal hazard properties of reactive chemicals from DSC experiments is illustrated by the results of SADT simulations performed with azobisisobutyronitrile (AIBN). The kinetics of decomposition of AIBN in the solid state was investigated in a narrow temperature window of 72-94 °C, just below the sample melting. The kinetic parameters of the decomposition were evaluated by differential isoconversional method. The very good fit of the experimental results by the simulation curves, based on the determined kinetic parameters, indicated the correctness of the kinetic description of the process …

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ICTAC Kinetics Committee Recommendations for Collecting Experimental Thermal Analysis Data for Kinetic Computations

The present recommendations have been developed by the Kinetics Committee of the International Confederation for Thermal Analysis and Calorimetry (ICTAC). The recommendations offer guidance for obtaining kinetic data that are adequate to the actual kinetics of various processes, including thermal decomposition of inorganic solids; thermal and thermo-oxidative degradation of polymers and organics; reactions of solids with gases; polymerization and crosslinking; crystallization of polymers and inorganics; hazardous processes …

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Parameters Influencing the Correct Thermal Safety Evaluations of Autocatalytic Reactions

The stability of live-attenuated viruses is very challenging due to thermal sensitivity; therefore, solid form is usually required (often freeze-dried products). Micropellet technology is a lyophilization technology that has the potential to provide greater flexibility in the presentation of a given vaccine particularly in multi-dose format or in combination of different vaccines. As a novel vaccine alternative process, this spray freeze-dried (SFD) micropellet technology was evaluated using as a model a yellow fever virus produced in Vero cells (vYF) …

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Scale-up Based on Advanced Kinetics. Influence of DTBP/Toluene Ratio on the Thermal Behavior of Samples in mg, kg and ton-Scales

The runaway reactions are generally investigated by the time-consuming Accelerating Rate Calorimetry (ARC) or in isothermal (ISO-ARC) or heat-waitsearch (HWS) modes. In present poster we discuss the application of the Differential Scanning Calorimetry (DSC) for the determination of the Time to Maximum Rate under adiabatic conditions (TMRad) of various concentrations of Ditert- butyl peroxide (DTBP) in toluene. Additionally we present the method of simulation of the course of ARC experiments …

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Kinetic Evaluations for the Transportation of Dangerous Chemical Compounds

Current legislation about goods carriage (ADR – Agreement Concerning the International Carriage of Dangerous Goods by Road) sets the determination of several parameters related to the conditions of the used containers. Several of these parameters are required for the substance classification and the definition of the precautions to be adopted during transportation. One of the main potential hazards during freight is related to the thermal decomposition of the substance. Testing for the identification of decomposition in the carriage conditions can be time consuming and expensive, therefore different solutions have been attempted to simulate thermal behaviour of chemical compounds during transportation …

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Consideration of Autocatalytic Behavior in Determination of Self Accelerating Decomposition Temperature

When determining Self Accelerating Decomposition Temperatures (SADT) for shipment purposes, the kinetics of the decomposition reaction of the materials must be known. The simplified models assuming the first order decomposition kinetics are generally applied, however this traditional approach fails in correct SADT determination for autocatalytic and multistage overlapped reactions. For these cases a more universal, yet easily implemented, advanced method will be presented in which the detailed kinetic mechanism does not need to be known to correctly predict SADT …

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Estimation of Time to Maximum Rate under Adiabatic Conditions(TMRad) using Kinetic Parameters derived from DSC – Investigation of Thermal Behavior of 3-Methyl-4-Nitrophenol

Kinetic parameters of the decomposition of hazardous chemicals can be applied for the estimation of their thermal behavior under any temperature profile. Presented paper describes the application of the advanced kinetic approach for the determination of the thermal behavior also under adiabatic conditions occurring e.g. in batch reactors in case of cooling failure. The kinetics of the decomposition of different samples (different manufacturers and batches) of 3-methyl-4-nitrophenol were investigated by conventional DSC in non-isothermal (few heating rates varying from 0.25 to 8.0 K/min) and isothermal (range of 200-260°C) modes …

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Determination of SADT and Cook-Off Ignition Temperature by Advanced Kinetic Elaboration of DSC Data

The exothermic decomposition parameters of a single-base propellant were obtained using differential scanning calorimeter (DSC) tests conducted at various heating rates. The DSC signals were processed using the Friedman isoconversional method to compute activation energy as a function of conversion. There was excellent agreement between the experimental and the simulation plots, which confirms the validity of the kinetic model used to describe the propellant’s exothermic decomposition. The kinetic parameters and heat balance were subsequently analyzed and used for a simulation of cookoff experiments conducted at different experimental rates (heating rates 3.3 – 1.0 K/h and a heat-wait-search mode) …

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