Synthesis and evaluation of polyurethane foam composites for enhanced sound absorption at low frequency

Abstract

Polyurethane foams are extensively used as sound absorbing materials in various automobile parts. However, the sound absorption capability of polyurethane foam ispoorin low frequency range. The advancement of technologies to develop newerpolymer composites, provide scope to develop composite polyurethane foam with better sound absorption coefficient in low frequency range. Composite foams are made with two different filler materials as crumb rubber and coconut fiber, in varying weight fraction of up to 2.0%. Density, Sound absorption coefficient, and Noise reduction, measurements were done on all polyurethane foams. The effect offiller additionsto polyurethane foams ondensity and sound absorption coefficient at low frequency are discussed.The 1.4 % crumb rubber polyurethane foam offers the best combination of low density, improved sound absorption coefficient value and noise absorption at low frequency.