Fabrication of a sandwich panel by integrating coconut husk with polyurethane foam and optimization using R2

As the need for a sustainable solution increase, waste materials are gaining popularity in building applications to reduce the environmental impact. This study aims to utilize the waste Coconut Husk (CH) and Calcium Silicate Board (CSB) in a sandwich panel where Polyurethane Foam (PU) is used as a binding material which consists of A (isocyanate) and B (polyol) with a mixing ratio of A: B at 1:1.2. CH is obtained as a residue from the production of coconut shells aggregate. The PU has been replaced with CH at 10, 20, 30, 40 and 50 %, to identify the optimum replacement level. Sandwich panels of dimension 30 x 30 cm with a core thickness of 2 and 3 cm was prepared and tested to categorize their mechanical properties, thermal properties, durability properties, characterization study and sound absorption coefficient. The results show that the PU replaced with 20 % of CH has higher compression and flexural properties, owing as an optimum percentage. The inclusion of CH in the PU reduces the cell size and yields a significant improvement in acoustic behavior up to a frequency of 1600 Hz. The regression model was analyzed with the experimental data and validated by the suitable R(2 )threshold accuracy as R-2 > 0.90.

Automated summary

This study aims to utilize waste coconut husk and calcium silicate board in a sandwich panel with polyurethane foam as a binding material. The results show that replacing polyurethane foam with 20% waste coconut husk can improve mechanical properties and acoustic behavior.