Optimization of Mechanical Properties of Heat-Treated and Epoxy-Coated <i>Gigantochloa scortechinii</i> Bamboo Under Seawater Exposure Using Response Surface Methodology

The demand for sustainable materials has increased due to environmental concerns and the need to reduce dependence on conventional construction materials. Natural fibers, particularly bamboo, have gained attention as eco-friendly alternatives for structural and marine applications. This study evaluated the mechanical performance of bamboo strips under different processing and environmental conditions. The investigated factors were the number of epoxy coating layers (one and two), heat treatment temperatures (160°C, 170°C, and 180°C), and seawater concentrations (0%, 50%, and 100%). The effects of these parameters on tensile and flexural properties were first assessed using analysis of variance (ANOVA). Response Surface Methodology (RSM) combined with the Desirability Function (DF) was then applied to develop predictive models and optimize the mechanical responses. The quadratic models showed satisfactory predictive capability, with coefficients of determination (R²) ranging from 66.76% to 95.55%. Optimal tensile performance was achieved with 1–2 epoxy coating layers, heat treatment temperatures of 163–165°C, and 0% seawater concentration. The highest flexural performance was obtained with two epoxy coating layers, heat treatment temperatures of 162–166°C, and seawater concentrations of 67–100%. These findings demonstrate that optimizing heat treatment, epoxy coating, and seawater exposure significantly enhances the mechanical performance of bamboo strips for sustainable marine applications.