Sustainable multifunctional foams for cold-chain packaging: Stabilizing polyethylene glycol with cellulose and pomegranate peel for antibacterial protection and temperature control

Abstract

Here, we developed multifunctional, bio-based foams specifically designed for cold-chain packaging. Polyethylene glycol (PEG 400) is integrated as a phase change material within a cellulose and pomegranate peel matrix. The foams exhibited high porosity, low thermal conductivity, and effective thermal regulation with a phase transition at around 2 °C, storing approximately 65 J/g of latent heat. Importantly, the foams demonstrated stable thermal behavior across repeated heating-cooling cycles, with no leakage of PEG observed. Antibacterial testing revealed significant inhibition of Staphylococcus aureus, and antioxidant activity reached close to 100 %, underscoring the foams' potential for microbial control and oxidative stability in temperature-sensitive applications. A life cycle assessment further supported the environmental benefits, showing a 25 % reduction in carbon footprint compared to conventional petroleum-based foams. Additional benefits were achieved over benchmark foams when material criticality was considered. Overall, this work introduced a sustainable packaging solution for cold-chain transport, combining temperature stability, antibacterial and antioxidant activities, and reduced environmental impact.