Thermo-physical properties evaluation of commercially available phase change material and engine oil

Phase Change Materials (PCMs) efficiently store and release latent heat during phase transitions, with Solid-Liquid PCMs being widely used in industries such as renewable energy and battery thermal management due to their ability to maintain a nearly constant temperature. However, challenges like low density, low thermal conductivity, and high viscosity necessitate customized solutions for specific applications. To address this, different Composites Phase Change Materials (CPCM) were prepared. To fabricate these materials commercially available PCMs and pure engine oil were used. Two different PCM samples (OM50 and OM42) were used. Ultrasonication method was used to make homogenised samples. The molecular structure was studied using Fourier Transform Infrared (FTIR) spectroscopy. Thermal analysis (TGA and DSC) indicate that the thermal behaviour of the samples change with the filling level of PCM in engine oil. TGA plots confirm the expected phase-change behavior, and composites with engine oil exhibit greater thermal stability by reducing mass loss at 300 °C. Reduction in melting point in the samples was observed due to reduction in intermolecular forces. Density measurements indicate that mixing does alter inter-moleculer interactions, the decomposition onset temperature remains unchanged, preserving the operational temperature range, while the blend with 40 % engine oil shows the lowest density, suggesting maximum dissolution of the organic PCM. Thermal conductivity in OM 50 varies by 25.3 %, while in OM 42 it changes by 16.5 % with increasing engine oil concentration. These results highlight the potential of high-performance organic PCM and engine oil composites for efficient and cost-effective energy storage systems.