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Thermochromic phase change materials (TPCMs) are gaining increasing interest among scientists. These multifunctional materials can store thermal energy but also, at the same time, during the phase transition, they can change colour. Thermal conductivity is also extremely important for this type of material, which is why various additives are used for this purpose. This work aimed to study the properties of thermochromic phase change materials with an inorganic modifier. Stearic acid, behenyl alcohol, and bromocresol purple were used as thermochromic system components, while boron nitride particles were used as an additive. The key tests for such systems are thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), which allow determining the thermal stability of the materials (at around 170 °C) and phase transition parameters (thermal energy storage of 300 J/g in the range of 40–75 °C). The thermochromic properties were tested, and satisfactory results were obtained. In the end, laser flash analysis (LFA) tests indicated that boron nitride improves the thermal conductivity of the organic thermochromic phase change material by almost 30%. The results showed that the tested materials have great potential as thermochromic phase change materials for thermal energy storage. [ABSTRACT FROM AUTHOR]

Wood characterized by desired mechanical properties and wood joining material is essential for creating wooden structures. The polymer adhesives are suitable for such applications due to the possibility of energy dissipation from stresses generated by wooden structures and the elimination of thermal bridging, which are common problems in metal joining materials. This research focuses on the thermophysical properties of the laboratory-prepared flexible and rigid polyurethanes to select an appropriate polymer adhesive. Our results showed that the highest thermal stability was in the case of the new PSTF-S adhesive, which reached 230 °C, but the lowest mass loss in the air environment was around 54% for the PS material. The mean thermal expansion coefficient for F&R PU adhesives was 124–164∙10−6 K−1. The thermal diffusivity of examined adhesives varied between 0.100 and 0.180 mm2s−1. The thermal conductivity, depending on the type of polyurethane, was in the 0.13–0.29 W∙m−1∙K−1 range. The relative decrease in thermal diffusivity after heating the adhesives to 150 °C was from 2% for materials with the lowest diffusivity to 23% for the PU with the highest value of heat transfer. It was found that such data can be used to simulate wooden construction joints in future research. [ABSTRACT FROM AUTHOR]

Understanding the thermal properties of zeolites is crucial for their industrial applications. This study explores the thermal stability and dehydration process of clinoptilolite using high-temperature X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Clinoptilolite's thermal decomposition was monitored from 25 °C to 1200 °C, with results analyzed based on its crystal structure. Principal components analysis (PCA) of the DRIFT spectra indicated progressive water removal and dehydration upon heating, leading to the formation of hydrogen bonds. Thermogravimetric analysis (TGA) revealed a two-step endothermic weight loss: initially, physically adsorbed water was lost up to 100 °C, followed by the removal of tightly bound water and hydroxyl groups until 800 °C. Clinoptilolite remained the dominant phase up to 800 °C, after which albite and cristobalite took over. Rietveld refinement showed that the sample initially contained 70% clinoptilolite, 24% albite, and 6% cristobalite. Above 800 °C, clinoptilolite disappeared, leaving 93% albite and 7% cristobalite. FT-IR spectra changes due to water loss were evident: drying of adsorbed water occurred up to 75 °C and minimal changes were observed from 75 °C to 135 °C, followed by further dehydration until 240 °C. Complete dehydration was confirmed by the disappearance of OH stretching vibration bands by 395 °C, consistent with TGA findings. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of DSC/TG/DTG thermal studies for PA6 polyamide, coal fuels and polyamide composites with these materials. The test results are aimed at comparing the thermal effects and behavior of these materials under high temperature conditions and are the basics to know of the creation and use of polymer composites with various coal fillers.

The paper presents the application of thermal analysis methods in the study of various materials: coal sludge, polymeric material and composites of a polymer with coal sludge (fraction of coal sludge in composites: 1%, 3% and 5%). TG/DTG/DSC curves obtained during measurements in air atmosphere were analyzed. Polymers are used in many industries, that is why their thermal characteristics are so important. On the other hand, the mining industry, forced to supply power plants better quality fuel, must perform more thorough coal cleaning. This results in a continuous increase in waste in the form of coal sludge. The best method of disposing of these wastes is thermal utilisation (combustion and co-combustion), as well as use in composites with other materials. The aim of the study was to demonstrate the effect of the addition of coal sludge to the polymer on the energetic effect and the rate of mass change of the material sample during the thermal process by TG/DTG/DSC methods.

Multicomponent cobalt phosphate–silicate glasses from P2O5–SiO2–K2O–MgO–CaO–Co2O3 system in which molar ratio of P2O5 to SiO2 is 41:6 and cobalt ions are gradually incorporated at the expense of magnesium and calcium ions were prepared via melt-quenched technique. The obtained amorphous solids were subjected to the thermal and spectroscopic studies and density measurements in order to gain information about the structure and physical properties. As DSC, XRD, FTIR and pycnometry techniques were applied, the glass transition temperature, specific heat change, crystallization temperature, density, molar volume, oxygen packing density and associated infrared spectra were collected for each glass. Then, the process of induced crystallization was performed on the selected glass samples. The related glass-crystalline materials were evaluated via XRD method. As a result, crystalline phases associated with crystallization temperature were identified. The alterations in determined parameters, stoichiometry of connected crystalline phases and features of infrared spectra allow to conclude the impact of cobalt ions on structure of analyzed glasses due to the direct dependence of structure, physical and thermal properties. The conducted research constitutes a basis for further analysis of cobalt phosphate–silicate glasses and makes a contribution to the knowledge concerning the phosphate glasses family. [ABSTRACT FROM AUTHOR]