فهرست نشریات علمی دسترسی آزاد ایران

The chemical stability and mechanical integrity of construction materials critically determine acoustic performance and indoor air quality in enclosed sound studios. This study investigated emission profiles, chemical degradation pathways, and microstructural behavior of kiln-dried spruce, urea-formaldehyde bonded Medium-Density Fiberboard (MDF), and aluminum honeycomb composites with epoxy or acrylic adhesives. Gas Chromatography-Mass Spectrometry (GC-MS) quantified time-resolved Volatile Organic Compound (VOC) emissions, including formaldehyde (45 µg/m²h from MDF), monoterpenes (~12 µg/m²h from spruce), and minimal emissions (<8 µg/m²h from composites) under controlled and hygrothermal aging conditions. Fourier-Transform InfraRed (FT-IR) spectroscopy tracked chemical changes, revealing hydrolysis of urea-formaldehyde bonds in MDF post-aging. Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray (EDX) spectroscopy confirmed excellent adhesive fillet formation in honeycomb-epoxy bonds, uniform pressure-sensitive adhesive layers, dense resin-embedded fiber matrices in MDF, and elemental composition (carbon, oxygen, silicon, aluminum) governing structural behavior. Finite Element Method (FEM) simulations validated stress distribution and mechanical resilience under operational loads. Results showed MDF formaldehyde emissions increased by 20% after humidity cycling due to resin hydrolysis, while composites exhibited exceptional dimensional stability and damping (tan δ > 0.15). The synergy of a low-emitting, dimensionally stable honeycomb composite substrate and a humidity-buffering wooden surface layer presents an optimized system. This research shows that controlling material chemistry—supported by microstructural and computational evidence—is essential for ensuring long-term indoor air quality and acoustic durability in sensitive built environments.