The Polymer Society of Korea

Abstract

Polyurethane foams (PUFs) are widely used in automotive industries for acoustic absorption due to their porous structure that dissipates sound via air friction and cell wall vibration. However, achieving strong sound absorption and mechanical stability at low density remains challenging. In this study, eco-friendly multidimensional fillers were incorporated into low-density PUFs to modulate cell openness. The cell openness varied with filler content, affecting airflow resistivity and tortuosity. Composites with optimized filler content showed enhanced broadband sound absorption along with improved thermal and mechanical stability. Rheological analysis assessed the viscoelasticity of polyol mixtures and curing behavior of polyurethane, which were used to control the stability of cell nucleation and growth during foaming. Therefore, this study presents a practical strategy to fabricate lightweight, high-performance foams by combining eco-friendly fillers with rheological control.