Effective changes in softwood cell walls, gas permeability and sound absorption capability of Larix kaempferi (larch) by steam explosion

More interest in larch (Larix kaempferi) has been taken because of a greater focus on environmental properties. Steam explosion is an inexpensive and facile approach for the increasing rate of drying and durability of wood. A significant improvement in gas permeability and sound absorption coefficient of steam-exploded larch wood relative to the control wood is observed. It is due to structural changes in the cell wall that is proved by Fourier transform infrared spectroscopy, field emission scanning electron microscope, X-ray diffraction, and Energy-dispersive X-ray spectroscopy. The average increase in SAC of steam-exploded samples is 33.33% higher than the control samples at a wide range of frequency 250-6400 Hz due to the increasing air permeability (190.1%). Color of treated larch wood changed to black due to several chemical reactions in the cell wall and reduced of –OH functionality during the steam explosion. These findings summarized that steam explosion affects softwood cellulose cell walls, and the cross-section surface of larch wood could be considered for improving acoustic comfort in the building.