Polyurethane composite foams including silicone-acrylic particles for enhanced sound absorption via increased damping and frictions of sound waves

Polyurethane (PU) foams are widely used in automotive applications for sound absorption products because of their easiness of manufacturing process and light weight characteristics. In this study, PU composite foams including silicone-acrylic filler particles were fabricated to examine the sound absorption properties. The filler particles acted as nucleation sites and led to the decreased cavity sizes until 2 wt% inclusions, but after this point the cavity sizes increased due to the particle agglomeration. The filler particle contents strongly influenced on the open and partial-open pore ratios and the sound absorption characteristics of the PU composite foams. The best sound absorption performance was achieved at 2 wt% silicone-acrylic filler particles with the smallest cavity size and the highest partial-open pore ratio. Therefore, applying appropriate types and contents of filler particles is critical to accomplish improved sound absorption properties in PU composite foams by developing well-defined cell morphology.