Cassava starch-derived aerogels as biodegradable packaging materials

Biodegradable and natural materials can provide transformational solutions to environmental issues, particularly those associated with ubiquitous fossil-resources-derived conventional polymers like polyolefin thermoplastics and polystyrene foam as packaging materials. Herein, a facile approach is presented for preparing biodegradable and biocompatible lightweight structural scaffolds as an alternative to conventional plastic-based packaging materials. A variable dosage of polyvinyl alcohol (PVA) is used along with cassava starch to govern the structural integrity, mechanical properties, and porosity of resultant aerogels. The incorporation of PVA as a strengthening precursor improved the compressive modulus of starch aerogel from 2.0 to 18.2 MPa. Hydrogen-based interactions between the starch and PVA components, as revealed by infrared spectroscopic and differential scanning calorimetric measurements, extended the structural integrity. The high and regulated porosity of these aerogels furnished significantly low density (0.13–0.21 mg mm−3). A 98.5% of the starch-PVA aerogel is converted to CO2 by the microbial consortia within 23 days, signifying excellent biodegradability of these aerogels. Moreover, cassava starch-PVA aerogel is demonstrated as alternative packing material to conventional non-biodegradable black plastic bags for growing, transporting, and transplanting young plants. The improved thermal stability (<270 °C), low density, good compressive modulus (2.0–18.2 MPa), and excellent biodegradability reveal the potential of starch-based aerogels as excellent alternatives to conventional polyolefin thermoplastics and polymer-foam-based packaging materials.