VISCOELASTIC FOAMS BASED ON MODIFIED TUNG OIL AND REINFORCED WITH RICE HUSK ASHES: PHYSICAL AND MECHANICAL CHARACTERIZATION

VIRGINIA RIBEIRO DA SILVA; M. A. MOSIEWICKI; M. I. YOSHIDA; M. COELHO DA SILVA; P. M. STEFANI; N. E. MARCOVICH

Florianopolis

Congreso; 12° Congresso Brasileiro de Polímeros (12°CBPol); 2013

Viscoelastic polyurethane (PU) foams based on modified tung oil, ethylene glycol and polymeric MDI and reinforced with rice husk ash were prepared by free-rise pouring method and characterized in terms of density, compression and dynamic mechanical behavior. The density of foams ranged between 50 and 90 kg/m3, depending on the position of the sample with respect to the foam rise direction and filler content. Compression modulus, compressive strength and storage modulus increase as foam density increase but decrease as rice husk ash concentration increases due to the detrimental changes induced by the filler in the foam cellular structure. As revealed by dynamic mechanical tests, the foams exhibited two different and broad thermal transitions, which maximum in temperature depends on filler concentration. However, densification strain exhibits the opposite behavior indicating that reinforced foams can sustain slightly higher deformations without collapsing, probably due to a reduced reactivity of the components induced by the filled.