Effects of ammonium persulfate on coconut wood (Cocos nucifera L.) cellulose, hemicellulose, and lignin polymers: Improved sound absorption capacity: Improved sound absorption capacity

The rational design of sound absorption boards made of wood materials is an attractive field of research. This article describes a simple and low-cost ammonium persulfate treatment on coconut wood cell walls (Cocos nucifera L.). Reaction parameters such as concentration of reactant and reaction time were optimized. The results of different instrumental characterization such as X-ray photoelectron spectroscopy, X-ray diffraction, attenuated total reflectance–Fourier transforms infrared spectroscopy, and scanning electron microscope supports the chemical alterations of the wood cell wall. The quantitative analysis of hemicellulose, cellulose, and lignin was performed. The significant changes in cell-walls enhanced average sound absorption coefficient at each frequency range: 60.4% at 500–1000 Hz (t = −10.593 and p < 0.001), 80.8% at 1000–2000 Hz (t = −4.798 and p < 0.001), 96.2% at 2000–4000 Hz (t = −58.527 and p < 0.001) and 83.0% at 500–64000 Hz (t = −51.261 and p < 0.001). It is due to the increment of gas permeability (288.3%, p = <0.001). These results could be beneficial for new research on wood-based sound absorption materials to regulate the acoustic environment in houses.