Cellulose–Starch Composite Aerogels as Thermal Superinsulating Materials

The demand for sustainable packaging materials is rapidly increasing due to growing environmental concerns over the impact of plastic waste. In this study, biodegradable, porous, lightweight, and high-surface-area microcrystalline cellulose-starch (MCC-S) hybrid aerogels were synthesized via supercritical carbon dioxide (SC-CO₂) drying. The samples were generated using five different MCC-S weight ratios and characterized for their morphology, crystallinity, and structural and thermal properties. When MCC and S were used together, aerogels with superior properties were obtained compared to those made from each component individually. Specifically, the 1:2 MCC-S aerogel exhibited the highest porosity (97%), the lowest density (0.058 g/cm³), and the lowest thermal conductivity (0.012 W/(m·K)) along with a high specific surface area (258 m²/g). Therefore, MCC-S aerogels are promising insulators for advanced packaging applications, potentially serving as a sustainable alternative to Styrofoam.