Enhanced thermal properties and dimensional stability of wood treated with phase-change materials for building energy storage applications

Abstract

This study investigated the thermal-energy storage (TES) properties of Scots pine wood impregnated with lauryl alcohol (LAOH) and methyl palmitate (MP). These phase-change materials (PCMs) were selected for their adaptability to different climatic conditions. To enhance dimensional stability and minimize leakage of PCMs, a 50:50 mixtures of PCMs and epoxidized linseed oil (ELO) was used. Comprehensive analyses were conducted, including water absorption (WA), water repellent efficiency (WRE), anti-swelling efficiency (ASE), mechanical properties, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and fourier transform infrared spectroscopy (FTIR). The results showed significant improvements in dimensional stability, particularly with the PCM-ELO combination. DSC results showed that melting enthalpies of 88.4 J/g for LAOH-treated wood and 100.8 J/g for MP-treated wood, with corresponding melting temperatures of 18.3 degrees C and 20.2 degrees C, respectively. These values remained stable phase transition temperatures even after 600 thermal cycles, demonstrating strong thermal reliability. Mechanical test revealed an improvement in the modulus of elasticity (MOE), with values of 18.31GPa for LAOH-treated samples and 18.13GPa for MP-treated samples. Thermoregulation tests indicated reduced temperature fluctuations, with peak temperatures during heating lowered by 7.2 degrees C and 6.5 degrees C for LAOH and MP treatments, respectively.