Sustainable Bio-Based Superabsorbent Polymer: Poly(itaconic acid) with Superior Swelling Properties

In this study, an environmentally friendly superabsorbent hydrogel, produced from the cross-linked poly(itaconic acid) (PIA) superabsorbent polymer (c-PIAS) based on itaconic acid (IA), was prepared using the radical polymerization method with potassium persulfate as an initiator and poly(ethylene glycol) diacrylate as a cross-linking agent. IA, which is water-soluble and has excellent biocompatibility, was selected as the monomer because it has attracted considerable attention as a substitute for petroleum-based polymers. The chemical structure and rheological properties were investigated based on the degree of cross-linking. The bio-based c-PIAS showed the highest water absorption capacity of 370.7 g/g and an exceptional reswelling capacity of 1713.8 g/g. These absorption properties were analyzed by applying them to swelling kinetics (i.e., pseudo-second-order kinetics and Fickian diffusion), which revealed an excellent relationship. In addition, c-PIAS demonstrated excellent low-temperature maintenance capability, indicating promising applicability for producing commercial ice pack. Therefore, the bio-based c-PIAS has the application potential for sustainable chemical industry including hygiene products and environmental packaging.