Functional Aerogel Derived from Postconsumer PET Bottle with Integration of Dynamic Imine Linkages

Waste management of postconsumed PET bottles through unique recycling strategies is a crucial step for sustainability and circular economy in plastic materials. In the present study, the vitrimerization process is adopted for making waste PET bottles into functional aerogels by incorporating dynamic imine cross-linkers, which possess high potential to physically cross-link with PET oligomers. The dynamic imine cross-linkers were synthesized via aldimine condensation between an aldehyde and a diamine to prepare a vitrimer aerogel. The prepared aerogels have densities in the range of 0.164–0.205 g cm–3, with porosity values between 83% and 86%. The samples displayed reasonable mechanical properties with compressive modulus values ranging from 1.2 to 1.5 MPa and good thermal stability. Furthermore, the aerogel materials displayed good solvent absorption capacity (2000–5000 mg/g) and excellent oil–water separation performance over multiple cycles. The aerogels also showed high acid stability, even at a pKa value of −6, indicating their potential applicability under harsh environmental conditions. Reprocessability of material from the fabricated aerogel is readily achievable by treating the aerogel in an excess amine solution and can be recycled to prepare PET sheets by hot pressing. Thus, this circular approach paved the way to develop a vitrimeric functional aerogel from PET waste for mitigating oil contamination in water bodies.