ETD

• PCM
• polyurethane foams
• PU

This thesis aims to study in depth the chemical and physical properties of bio-based polyurethane (PU) foams incorporating microcapsules containing phase change materials (PCMs). The core idea of this research is to combine the excellent insulating performance of polyurethane foams with the heat storage and release capacity of PCMs, thus creating a material that limits heat loss and improves energy comfort. The PCM used is a commercial product (EnFinit® PCM35CP) that exhibits a solid-liquid transition in the temperature range of interest for building applications. These capsules are incorporated in different percentage fractions (e.g., P0, P5, P10, and P15) to evaluate how the amount of PCM and its distribution influence the overall behavior of the panel. Various analyses were subsequently performed for the different characterization areas. From a chemical and morphological perspective, established techniques such as FTIR spectroscopy, which allows monitoring of functional groups and cross-linking progress, and optical or electronic microscopy (stereomicroscopy and SEM), which allow observation of capsule dispersion, cell size and uniformity, and the interface between the microcapsule and the matrix, will be used. These analyses are crucial for understanding whether the inclusion of PCMs compromises the foam's cellular structure or, conversely, improves some of its characteristics. Thermoanalytical analyses were also conducted. DSC analysis was used to determine the PCM's melting and solidification profiles and to quantify the energy that can be stored by the panel. Thermogravimetric analysis (TGA/DTG) tests allowed evaluation of the foam's thermal stability and identification of the different stages of degradation. These analyses were supplemented by other tests, such as the Hot Disk method, which allowed us to determine thermal conductivity, diffusivity, and equivalent heat capacity as a function of temperature. Finally, analyses were conducted for the mechanical response, in particular, static compression tests (Compressive Force-Deflection) and dynamic mechanical analyses (DMA), both at temperature and fatigue, with the aim of estimating the stiffness, damping, and stability of the material under repeated stresses. The objective was to verify whether the addition of PCM compromises the mechanical strength of the panel or whether it remains compatible with the structural needs of building and industrial applications. As a final analysis, to understand whether the material was safe, the reaction to fire was carried out. To this end, cone calorimetry was used under different heat flow conditions (35 kW/m² and 25 kW/m²), with and without ignition, monitoring parameters such as Heat Release Rate (HRR), Total Heat Release (THR), and smoke production (SPR and TSP).