Valorization of Corn Husk Waste into Citric Acid-Bonded Particleboards: Physical, Mechanical, and Acoustic Performance

Abstract The valorization of agricultural residues into engineered materials offers a sustainable pathway to reduce biomass waste and dependence on synthetic binders. In this study, corn husk (CH) was employed as the primary raw material to produce particleboards using citric acid as a natural adhesive. A single formulation with 0.6 cm thickness and 30% citric acid content was fabricated by hot pressing and subsequently characterized for its physical, mechanical, and acoustic performance. The physical tests revealed a board density of 0.85 g/cm 3 , water absorption of 24.95%, and thickness swelling of 88.5%, meeting the requirements of medium-density particleboards. Mechanical evaluation showed a modulus of rupture ( MoR ) of 5.59 MPa and a modulus of elasticity ( MoE ) of 590.3 MPa, indicating adequate structural integrity for non-load-bearing applications. Acoustic measurements using the impedance tube method demonstrated frequency-dependent sound absorption behavior. The highest absorption coefficient ( α ) was recorded at low frequency (100 Hz) with α = 0.763, while moderate absorption was observed at mid-frequency ranges (500 Hz, α = 0.674) and low performance at higher frequencies (>1 kHz, α < 0.20). These findings suggest that citric acid-bonded CH particleboards exhibit promising properties as biodegradable and eco-friendly materials with potential applications in acoustic insulation and sustainable construction.