Biomacromolecules, Vol.20, No.3, 1401-1411, 2019
A Study of the Physical and Mechanical Properties of Aerogels Obtained from Bacterial Cellulose
Aerogels with a density of 4.2-22.8 kg/m(3) were obtained from bacterial cellulose synthesized under static and dynamic cultivation conditions on a molasses medium. The strength properties and porous structure of the aerogels strongly depended on their density. With an aerogel density of 22.8 kg/m(3), the modulus of elasticity at 80% compression of the sample was 0.1 MPa. The decrease in the density of aerogels led to an increase in the pore sizes ranging from 20 to 1000 mu m and a decrease in the modulus of elasticity. These characteristics were more pronounced in aerogels obtained from bacterial cellulose under static cultivation conditions. The aerogels had a low coefficient of thermal conductivity (0.0257 W m(-1)degrees C-1), which is comparable to the thermal conductivity of air, and moderate thermal stability because the degradation processes of the aerogels began at 237 degrees C. The aerogels obtained from bacterial cellulose had high sound absorption coefficients in the frequency range of 200-5000 Hz, which makes it possible to use the aerogels as heat- and sound-insulating materials.