Metallic solidification structures show a huge variation of patterns, which may be observed in many solidification processes such as casting and welding. To improve our understanding of the formation of these patterns, directional solidification experiments are carried out by using the Bridgman-technique. Hereby, not only metal alloys are investigated, model substances are also considered for this purpose. Such model substances consist of transparent organic components with a non-facetted high temperature (simply called plastic) phase. These organic components solidify like metals, which have the advantage of being able to observe the formation as well as the dynamics of solidification patterns with a standard light microscope. Studies on the formation of layered peritectic solidification structures have been carried out by using the model system TRIS-NPG. So far only very few binary organic systems reveal a peritectic region which is suitable for such experiments. For these rare systems, and especially for the TRIS-NPG system, there is insufficient knowledge of corresponding physical and chemical properties. As further studies on peritectic layered structures are planned on board of the ISS for 2019, it is of utmost importance to discover more about the specific properties of this type of material. Therefore, partial complimentary studies on thermal conductivity, vapor pressure, and viscosity for peritectic concentrations were conducted. The corresponding values are needed for the correct interpretation of the dynamics of peritectic pattern formation, within a temperature gradient in a Bridgman furnace using this model system.