Sustainable construction materials from leveraging water hyacinth and wastepaper for superior sound absorption and thermal insulation

Abstract

This study investigates the feasibility of utilizing water hyacinth (WH) and wastepaper (WP) as sustainable materials for developing thermo-acoustic panels in construction applications. WH, an invasive aquatic plant, and WP, a byproduct of handicraft paper production, were combined in varying proportions to evaluate their physical, mechanical, thermal, and acoustic properties. Key parameters assessed included density, porosity, flexural modulus of elasticity, thermal conductivity, and sound absorption performance. The results revealed that WH-rich composites exhibited high porosity and superior sound absorption, making them well-suited for absorption applications. Conversely, WP-rich composites demonstrated enhanced mechanical strength and thermal stability due to their denser structure. Thermal analysis using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) indicates that WP-rich samples are more thermally stable, with reduced heat release during decomposition. SEM analysis supports these findings, showing that WH100 possesses a highly porous structure conducive to sound absorption, while WP40 and WP50 exhibit a compact fiber network, enhancing mechanical properties but slightly reducing acoustic absorption. Flammability testing confirmed HF1 classification across all samples, highlighting their fire safety suitability. Economic analysis showed that WP-based panels were more cost-effective, with WP50 achieving the lowest production cost at 539.99 THB/m2, while WH-based composites excelled in sound absorption. Among the formulations, WP10 emerged as a standout for its balance of acoustic performance, thermal insulation, and eco-friendliness, making it competitive with conventional materials such as rock wool and glass wool. This study establishes WH and WP composites as viable, eco-friendly alternatives for construction materials, contributing to sustainable building practices while addressing environmental challenges through the repurposing of agricultural waste.