The development of sound-absorber porous of sponge foam rubber with addition corn cob carbon

Abstract

The synthetic foam rubber was reinforced by powder corn cob charcoal with 0, 5, 10 and 15 phr additional content. The foam rubber was estimated the physical properties such as density, hardness (Shore scale A), tensile strength (ASTM D638) and sound absorption coefficient (ASTM C 384 – 04). The foam rubber microstructure was investigated by stereo microscope and scanning electron microscopy (SEM). It was found that the density and hardness of rubbers foam were presented in the range of 0.13-0.33 g/cm³ and 1.1-11.1 Shore A, following, that were increased with high corn cob charcoal content. The results of tensile strength and modulus from foam rubber with vary corn cob charcoal addition, it was shown the like-brittle polymer and the increased high strength while the elastic modulus associated to reduce with increased charcoal contents.  The sound absorption coefficient for the frequency between 700 to 6400 Hz of charcoal addition 0 and 5 phr were presented the range of value 0.52-0.83 and 0.35-0.98, according. Then, the charcoal additive 10 and 15 phr were presented the high frequency adsorption between 700 to 6400 Hz, sound coefficient 0.33-0.60. Finally, the addition 5 phr corn cob charcoal had high sound coefficient. The morphology of foam, the porosity size was reduced with high charcoal content. The charcoal particles were good distribution in rubber foam and supported the high adhesion of foam structure. Finally, the different foam structure was effect form charcoal corn cob particles content. It was effected the sound absorption coefficient behavior in rubber foam.