A Green Dual Function Engineering Material-Sound Absorption and Heat Insulation Based on Water Hyacinth Fiber and Waste Palm Oil

A green dual function engineering material, sound absorption and heat insulation from water hyacinth fiber (WHF) and used palm oil-based polyurethane adhesive composite, has been successfully established via in situ polymerization by compression molding. The ratio of weight of composite material to volume of mold has been studied and varied from 50 to 70%w/v of mold by fixing the ratio of WHF/PU and isocyanate index or NCO index equal to 60/40 and 100, respectively. The material density of materials, humidity absorption, mechanical properties, morphology, sound absorption and heat insulation properties were evaluated. The findings revealed that the density of the material is a crucial factor in determining its sound absorption and heat insulation properties. The composite with 60%w/v of mold exhibited the highest sound absorption coefficient and heat insulation when compared to the composites with 50 and 70%w/v of mold. This is due to the lower density of the composite, providing ample space between the reinforced fibers to dissipate sound, heat, or energy within the material. Based on these results, it can be concluded that the developed material has the potential for use in sound absorption and thermal insulation applications, particularly for sound and thermal lining of walls and roofs.