Sustainable development, optimization, and simulation of bio-based polyurethane foam composites for enhanced building acoustics

This study focuses on developing a bio-based polyurethane foam (PUF) composite by integrating nanofillers such as carboxy-methyl cellulose (CMC), magnesium oxide (MgO), and bamboo charcoal (BC) into the PUF using a poly-vinyl-alcohol (PVA) and borax slime matrix through the dip-coating process. The objective of the research is to reduce room noise across a broad frequency range and compare the experimental results with optimization and simulation. Response Surface Methodology (RSM) with Central Composite Design (CCD) was used to design experiments and optimize the parameters affecting the acoustic performance of the samples, determining the weight percentages of the nanofillers as input parameters and using the noise reduction coefficient (NRC) as the output response. The sound absorption coefficient (SAC) was measured using an impedance tube, adhering to ASTM Standard E-1050. Field emission scanning electron microscope (FESEM) imaging visually confirms the size, shape, and uniformity of nanofillers in the PUF, while fourier transform infrared (FTIR) spectroscopy further verifies the presence of organic and inorganic compounds. According to the CCD results, the combination of 2.35 wt% CMC, 10 wt% MgO, and 25 wt% BC yielded the highest NRC value of 0.343. A confirmation sample was then prepared, and its NRC was measured, resulting in a value of 0.327. COMSOL Multiphysics 6.0 simulated the SAC of the optimized sample using the JohnsonChampoux-Allard (JCA) model for validation. According to the SPL plot, the confirmation sample's average sound pressure level (SPL) reduction ranges from 2 to 44 dB. The findings indicate that bio-based PUF composites could be highly effective for sound absorption in building interiors and other indoor enclosures, making them a promising solution for sustainable construction and building materials.