Thermo-modified native black poplar (Populus nigra L.) wood as an insulation material

Abstract

Extensive research projects have been carried out on thermal modification of wood material, yet thermal properties of thermally modified poplar wood have not been comprehensively investigated. Black poplar (Populus nigra L.) is a Eurasian species native to Italy which is rarely used for the production of highperformance products, though it is one of the least expensive hardwoods on the market. To explore alternative applications of poplar wood such as building facade or fire resistance materials, reliable data of thermal behaviour of thermally modified wood at high temperatures are needed. In this work, the thermal behaviour of native black poplar wood after thermal modification at different temperatures (180 °C, 200 °C and 220 °C) was analyzed. Thermal conductivity, thermal diffusivity and porosity were measured on poplar wood boards, as well as mass loss and wood color changes after heat treatment were quantified. Thermal conductivity of wood samples showed significant changes after treatment at 200 and 220 °C, but not at 180 °C. Wood porosity showed significant differences with the control when the samples were modified at a temperature of 220 °C. Increasing color differences were observed in wood samples by increasing the thermal modification temperature. Also, the mass loss of wood samples increased and equilibrium moisture content significantly dropped down after thermal modification. Our results showed that the use of thermally-modified black poplar wood could be considered as a viable alternative to chemically treated wood products for specific applications where high insulation is needed, such as saunas or windows, and for façades elements.

Effects of sepiolite addition to acrylic-latex paint on pull-off adhesion strength in nanosilver-impregnated and thermally-modified beech (Fagus orientalis L.) wood

“…The general decrease in all heat-treated treatments is attributed to multiple factors. The first and probably the most important factor is the thermal degradation of cell-wall polymers (mostly cellulose and hemicelluloses) as a result of thermal modification 4 , 5 , 7 , 9 – 12 , 20 , 45 . The decreasing trend in the pull-off strength of the thermally-modified specimens is consistent with previous studies, though the type of finishes and paints would be influential in the final results of pull-off strength 44 .…”

“…Condensation of lignin is another factor that causes a decrease in the mechanical properties of solid wood, partially influential in the decrease in the pull-off strength of the heat-treated specimens 5 , 47 . Thinning of the cell wall, and the occurrence of microscopic cracks in it, is also a well-known side-effect of condensation of lignin and thermal modification 4 , 5 , 7 , 9 , 11 , 12 , 20 , 45 having a deteriorating effect on pull-off adhesion strength values.…”

Caring for the forests of an inland area in the era of climate change: a case study of Basilicata, Southern Italy

“…Ci sono già in questo campo applicazioni in grado di generare, attraverso l'impiego di legno prodotto localmente, valore aggiunto in vari settori industriali. Diversi studi condotti da ricercatori dell'Università della Basilicata in partenariato con l'industria del legno su legname proveniente da foreste lucane, hanno dimostrato ad esempio l'efficacia dei trattamenti igrotermici per il miglioramento delle caratteristiche dei prodotti legnosi, con importanti ricadute sul settore dell'arredo (Todaro 2012, Ferrari et al 2013, Lovaglio et al 2019, Todaro et al 2021) oppure per la costituzione di pannelli di particelle coibentanti o per pannelli da tavole (Tiwari et al 2023). Promettenti appaiono anche i metodi estrattivi, con applicazioni ad alto valore aggiunto nel settore farmaceutico e nutraceutico (Cetera et al 2019, Faraone et al 2021.…”

Characteristic Properties of a Bamboo-Based Board Combined with Bamboo Veneers and Vacuum Heat-Treated Round Bamboo Sticks

“…Jebrane et al [ 34 ] and Pockrandt et al [ 35 ] evaluated the influence of steam heat treatment and VH treatment on the chemical, physical, and mechanical properties of woods. Todaro et al [ 36 ] measured the thermal properties (thermal conductivity and diffusivity) and physical properties (porosity, mass loss, and surface color) of VH-treated black poplar ( Populus nigra L.) wood. Furthermore, Lin et al [ 32 ] reviewed the several advantages of heat treatment with vacuum for wood: (1) efficient drying; (2) decreasing odor of heat-treated wood; (3) greater color homogeneity on the surface of wood; (4) efficient reduction of hygroscopicity of wood heated under vacuum compared to other media; (5) high reactivity of wood thermal degradation; (6) easier and cheaper management for produced volatile wastes; and (7) treatment with reduced energy consumption and duration.…”