Biobased porous acoustical absorbers made from polyurethane and waste tire particles

G. SOTO; A. CASTRO; N. VIACHETTI; F. IASI; A. ARMAS; N. E. MARCOVICH; M. A. MOSIEWICKI

POLYMER TESTING

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2017 vol. 57 p. 42 - 51

0142-9418

The production of flexible polyurethane foams (FPF) with good acoustical performance to control soundand noise and incorporating bio/recycled raw materials is an interesting alternative to conventionalacoustic absorbent materials. In this sense, biobased polyols like glycerol (GLY) or hydroxylated methylesters derived from tung oil (HMETO) as multifunctional polyols, and waste tire particles (WTP) as fillersof low thermal conductivity and good capability for acoustical absorption, are prospective feedstocks forFPF preparation. In this work, FPF were prepared by adding different amounts of these components to aformulation based on a commercial polyether polyol. Results of scanning electron microscopy (SEM)analysis, compression tests and normal-incidence sound absorption coefficient (aN) measurements arepresented and discussed. The addition of WTP or GLY to the commercial formulation enhanced both themodulus and yield stress of the obtained FPF in all cases. Moreover, a high recovery of the applied strain(>90%) was attained 24 h after the compression tests. On the other hand, the normal-incidence soundabsorption coefficient, aN, reached high values mostly at the highest evaluated frequencies (aN ~0.62-0.89 at 2000 Hz and aN ~0.70-0.91 at 5000 Hz). SEM micrographs revealed that the foams obtainedpresent a combination of open and closed cell structure and both the modifiers and particles tend todecrease the cell size.