Author(s): SAKAZAKI, E. M.; CARVALHO, L.; ANDREANI, L.; LUZ, S. M. da; VALADARES, L. F.

Summary: Abstract: This study focuses on producing aerogels formed by cotton microfibrillated cellulose (MC), natural rubber latex (NR), and their nanocomposites. MC was produced through high-speed mechanical shear processes, enabling its dispersion in an aqueous medium. The nanocomposite's production occurred by blending the aqueous dispersions of microfibrillated cellulose (0.26 wt %) and the natural rubber latex (1 wt%), followed by freeze-drying. The morphology and thermal properties of aerogels were evaluated using scanning electron microscopy (SEM), thermogravimetry analyses (TGA), and differential scanning calorimetry (DSC). Aerogels with different proportions were prepared to comprehend each component's effects in the nanocomposite. Microscopy revealed the effectiveness in obtaining cellulose micro- and nanostructures using shear. All samples presented a very porous structure. The preparation of the nanocomposites allowed the uniform incorporation of cellulose into rubber despite the intrinsic differences between their composition and chemical properties. The increase in rubber the proportion promotes greater interconnectivity of macropores, rendering them denser and losing the laminar and microporous characteristics observed in aerogels with higher cellulose ratios. The aerogels exhibited satisfactory thermal stability at around 300 °C, underscores the effectiveness of the aerogel synthesis process in obtaining cellulose micro- and nanostructures through mechanical processes and in nanocomposite formation through aqueous medium followed by freeze-drying.

Publication year: 2024

Types of publication: Paper in annals and proceedings

Unit: Embrapa Agroenergy

Keywords: Cotton, Nanocomposites, Rubber, Thermal properties