Balancing Mass Fraction and Performance of Corn Husk/PLA Biocomposites for Moderate-Load Furniture Applications

Corn husk is widely available as an agricultural by-product, yet its use in higher-value composite materials is still limited. This study examined how corn husk mass fraction affects the performance balance of corn husk/poly(lactic acid) (PLA) biocomposites (CHB) intended for moderate-load furniture board components. CHB containing 10 wt% and 30 wt% corn husk was prepared by hot pressing at 200 °C, 10 MPa, and 5 min. Density, water absorption, tensile, compressive, and flexural strength, Shore D hardness, and screw withdrawal resistance were evaluated. Increasing corn husk content from 10 wt% to 30 wt% reduced tensile strength, Shore D hardness, and screw withdrawal resistance. However, flexural strength increased from 22.8 ± 0.5 to 39.8 ± 1.1 MPa, while density decreased from 1.30 ± 0.03 to 1.09 ± 0.05 g/cm3. By contrast, 10 wt% CHB showed higher Shore D hardness and screw withdrawal resistance, reaching 84.1 ± 1.4 and 528.9 ± 22.9 N, respectively. The results indicate that 30 wt% CHB is more suitable for lightweight board components where flexural load-bearing is prioritized, whereas 10 wt% CHB is preferable for parts requiring higher surface hardness and screw connection reliability.