High-Strength and Biodegradable Golf Tees Fabricated from Solid Waste-Based Composites Using Discarded Chestnut Shells as Raw Material

Background: With the growing popularity of golf, the wood consumption and white pollution caused by traditional wooden and plastic golf tees create an urgent need for green, degradable, high-performance alternatives. Materials and Methods: To address this, a novel approach for the green fabrication of high-performance composites was developed utilizing a single agricultural solid waste (chestnut shells) bridged by an extremely low proportion (4 wt%) of a thermoplastic agent (polylactic acid, PLA). A mild dilute hydrochloric acid hydrothermal pretreatment selectively removed hemicellulose to expose active hydroxyl groups, followed by a wet hot-pressing process optimized at 80 °C, 4 h, 15 MPa, and 180 mesh. Results: Under these conditions, the resulting CS-APLA composite tees exhibited a bending strength of 86.32 ± 6.46 MPa and a dynamic impact toughness of 104.89 ± 5.26 kJ/m2, representing significant increases of 64.86% and 41.69%, respectively, compared to the pure biomass material, and outperforming conventional commercial wooden tees. A 75-day soil burial test demonstrated a weight loss of approximately 45.42%, confirming a balanced degradation rate. Conclusions: Multi-scale characterization confirmed that the synergistic reinforcement relies objectively on an acid-treatment-induced hydrogen-bonding network coupled with in situ polymer-bridged microdomains formed by PLA flow filling during hot-pressing. This study provides a sustainable route for the high-value utilization of agricultural solid waste.