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The work considers the methods and techniques, allowing the assignment of the kinetic mechanisms to the chemical reactions evaluated from signals of thermoanalytical measurements. It describes which information about the kinetic mechanisms can be found from either model-free or model-based methods. The work considers the applicability of both methods and compares their results. The multiple-step reactions with well-separated peaks can be equally analyzed by both methods, but for overlapping peaks or for simultaneously running parallel reactions the model-free methods provide irrelevant results.Keywords Model-free analysis Á Model-based analysis Á Kinetics of multi-step reactions Á NETZSCH Thermokinetics

Through the use of thermogravimetry (TG), this work explores the thermal degradation mechanism and kinetics of Kapton (polyimide) film. Isoconversional kinetic methods, which provide activation energy as a function of degradation, present insight into the development of a five-step competitive and consecutive kinetic model. To evaluate the accuracy and validity of the model, a statistical analysis of the implemented kinetic model is also presented. Coupled TG-mass spectroscopy and TG-Fourier transform infrared analysis were used to investigate the decomposition mechanism and to more fully explain the complex, heating-rate-dependent, decomposition pathway of Kapton.

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Next-generation additive manufacturing processes based on UV-curing acrylate photopolymers extend the barriers of functional part production by deploying rapid processing speeds, complex geometries with high resolutions, and an extended material spectrum. Many technologies introduce temperature-dependent curing and decomposition behavior of acrylates to the list of process-related challenges. This investigation targets a comprehensive analysis of the curing behavior and thermal stability of acrylic photopolymers by implementing analyzing techniques like thermogravimetric analysis, Fourier-transform infrared spectroscopy, and differential scanning calorimetry. Significant parameters such as the UV intensity and the isothermal temperature are varied based on the design of experiments. Characteristic evolving gases at elevated temperatures are identified and discussed towards their relevance for the curing process. The calorimetric results demonstrate increasing reaction speeds with elevated UV intensities as well as a restricted accelerating effect of increasing temperatures. The reaction enthalpy proves to be strongly dependent on the chosen temperature. The results represent the base for the comparison of different kinetic curing models in future investigations.

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