Research on sound absorption properties of hydrogenated carboxyl nitrile rubber/four-hole hollow polyester fibre composites

Abstract

A series composite was prepared by adding hydrogenated carboxyl nitrile rubber (abbreviated HXNBR) as the matrix and four-hole hollow polyester (abbreviated FHHPF) as the reinforcement. The sound absorption properties of these composites were studied. The results show that with the increasing of FHHPF quantity, the storage modulus increases and the loss factor decreases gradually. On the contrary, the sound absorption performance of the composite was improved continuously. Composite with 40% FHHPF in 1 mm thickness is the best. The sound absorption coefficient reached to 0.651 at 2500 Hz and the effective frequency range of absorption coefficient above 0.2 was 1750-2500 Hz. When the amount of FHHPF increased to 50%, negative effects of overuse shown up, that led to the decreasing of the sound absorption property. With a constant mass ratio 70/30 of HXNBR/FHHPF composite, the sound absorption performance can be enhanced by changing its thickness. However, the improvement was smaller after the thickness increased to 2 mm. When increasing the thickness above 2 mm, the improvement of sound absorption performance tended to move to the middle and low frequency. In the meantime, the tensile mechanical properties of the composite were significantly improved by adding FHHPF. Tensile tenacity was improved greatly and the breaking elongation is significantly decreased. The deformation of the composite was smaller and more stable, which was beneficial for the actual engineering practice.