Advancing sustainable molded packaging: Integrating silica aerogel into recycled paper pulp for the fabrication of thermally and mechanically stable superhydrophobic composites

In recent years, the growing demand for sustainable packaging has significantly fueled the quest to explore novel approaches that enhance the applicability of renewable alternatives. This study leverages the unique properties of silica aerogel (SA) to address the limitations of traditional molded pulp products. By integrating SA into recycled paper pulp (RP), we aimed to improve water resistance, thermal stability, and mechanical properties. Composites were prepared with varying SA concentrations (1-10 %). Contact angle measurements showed enhanced hydrophobicity, with RP/SA3 % achieving a contact angle of 152.09 degrees, compared to 122.39 degrees for neat RP. The tensile index (TI) of RP/SA composites with 3 % SA increased by 21.09 % compared to neat RP, indicating better mechanical strength. Thermal conductivity significantly decreased, with RP/SA10 % reducing from 0.155 W m- 1 center dot K- 1 in neat RP to 0.088 W m- 1 center dot K- 1, a 43.2 % improvement in thermal insulation. Additionally, composites with 1 % and 3 % SA maintained high biodegradability, showing over 50 % degradation after six weeks in soil. These results suggest that incorporating SA into RP composites enhances their functionality without compromising biodegradability, offering a promising solution for sustainable packaging. As regulatory bodies emphasize resource management and waste reduction, the potential of these innovative and environmentally friendly packaging solutions becomes increasingly significant.