Properties of Pinus nigra Arn. wood impregnated with phase change materials for potential energy-saving building material
Ahmet Can, İsmail Özlüsoylu, Eser Sözen, Mehmet Emin Ergün
Abstract
In this research, Pinus nigra solid wood (SW) and myristic acid (MA) were prepared as a shape stable phase change material (PCM) using a vacuum impregnation method. Three different concentrations of wood samples such as 15 %, 30 % and 60 % were impregnated and a minimum of 8 % and maximum of 22 % weight gain was obtained. The impregnated samples were characterised by scanning electron microscope (SEM), fourier transform infrared spectrometer (FTIR), X-ray diffractometer (XRD) and differential scanning calorimeter (DSC) analyses and water uptake , resistance to fungal decay , modulus of rupture , modulus of elasticity , compressive and tension strength parallel to the fibers of the samples were tested. The maximum weight increase after impregnation was 25 % and 60 % for the water uptake test samples. The most satisfactory sample was the 60 % modified wood which solidified at 53.50 °C with a latent heat of 26.1 J/g and melted at 51.01 °C with a latent heat of 24.7 J/g (medium-temperature zone (buildings fields)). After impregnation, FTIR and XRD analyses revealed no chemical interaction between MA and the wood. Wood was decomposed in a single stage at 367 °C, and MA-modified wood was decomposed at two different temperatures: 181–198 °C and 365–372 °C. At 60 % concentration, MA-modified wood samples showed resistance to T. versicolor fungus, and weight loss of less than 5 % was obtained. After 264 h in the water, the hygroscopic tests demonstrated that the MA/SW composite exhibited low water uptake and good anti-swelling efficiency (ASE). Wood samples impregnated with 60 % MA rose in modulus of rupture and modulus of elasticity , whereas compression and tension parallel to grain values decreased by 7 % and 5 %, respectively. The improvements in heat conductivity are almost 64 % more than the control wood (0.15 W/mK).