Thermal and sound insulation properties of pumice/polyurethane composite material

This study aimed to create a flexible composite material that can be used in special environments where heat and sound insulation is desired. Pumice with a grain size of 4.76-2.38 mm was mixed with 10, 20, 30, 40 and 50% polyurethane by volume. Sound absorption coefficient, sound transmission loss coefficient and thermal conductivity coefficient tests were conducted. Sound absorption coefficient and sound transmission loss coefficient values were measured in the frequency ranges of 50-1600 and 200-6400 Hz according to the ISO 10534-2 standard, using a device called 'impedance tube'. A Lasercomp Fox50 device was used to determine the thermal conductivity coefficient. As a result of these tests, it was determined that the values of sound absorption coefficient, sound transmission loss coefficient and thermal conductivity coefficient decreased at low frequencies as the pumice rate increased. It was observed that samples with 20 and 30% pumice rates gave the most effective results in low-frequency measurements and that samples did not exhibit a stable behaviour in high-frequency measurements. It was concluded that the pumice additive/polyurethane composite material could be a very suitable building material in terms of thermal and sound insulation.