Relating Thermal Properties to Potential Interactions between Compounds in Application and Recycling, Exemplified by Model Ink-Coating Component Mixtures

The purpose of this study is to determine how certain model compounds, representing in this case ink and typical coating components, interact in increasingly complex mixtures by evaluating their response to thermal treatment. Such materials are also used in many other chemical and industrial products and processes other than printing, such that the mechanisms are universally applicable. Thermogravimetric analysis (TgA) and differential scanning calorimetry (DSC) are techniques considered here as potential tools for the analysis. Fourier transform infrared (FTIR) spectrometry is used to characterize the model compounds and to provide a characteristic of the change undergone by some model compound mixtures after thermal exposure in TgA. To visualize the thermal data so as to combine the TgA and DSC measurements into a single comprehensible observation, a representation has been devised for the specific case of material evaporation and the respective observed specific evaporation energy, whereby the specific gravimetric change (TgA) and specific energy (DSC) ratios are calculated. By adopting this combinational representation, it is possible to clarify if there are observable interactions between studied model components. It is to be supposed that the thermal behavior of solvent in a given mixture will reflect, for instance, the ease with which an ink will set and dry to form a nonsmearing print, thus improving the efficiency of this and similar such processes. Additionally, any evidence of newly formed compounds, or material loss, resulting from thermal treatment during processing may affect product performance and ultimately recyclability or waste management