Sustainable and efficient delignification of Poplar and Chinese Fir wood using a peroxyacetic acid/ hydrogen peroxide system

This study explores a sustainable and eco-friendly approach for the rapid and uniform removal of lignin from poplar and Chinese fir wood. A comparative analysis of the chemical composition and structural properties before and after treatment was conducted. The results indicate that the mass loss rates were 30.72% for poplar and 31.30% for Chinese fir wood, with a corresponding decrease in relative lignin content by 95.46% and 88.40%, respectively. Additionally, the specific surface area increased by 6.37% for poplar and 30.85% for Chinese fir wood, while the pore size expanded by 3.50% and 19.50%, respectively. The relative crystallinity was increased by 31.51% for poplar and 16.41% for Chinese fir wood, and the O/C ratio rose by 19.65% and 29.54%. SEM images revealed that the cell walls of treated wood became noticeably thinner and slightly collapsed. The absence of characteristic lignin peaks at 1507 cm ⁻¹ , 1460 cm ⁻ ¹, and 1264 cm ⁻ ¹ confirmed effective lignin removal. The removal of lignin also resulted in a lower pyrolysis temperature, increased surface brightness, and reduced color variation. Due to the distinct internal structures and chemical composition of poplar and Chinese fir wood, the impacts of lignin removal varied, demonstrating significant changes in their properties. These finding provide a theoretical foundational for lignin removal of from wood, and lay the groundwork for the further wood functionalization.