Synthesis of super absorbent polymer using citric acid as a bio-based monomer

Abstract

Along with the up-rise of environment problems, ecofriendly materials that can replace existing products have become an issue. In the field of superabsorbent polymer (SAP), biobased monomers can be used to reduce petroleum based monomer, i.e. acrylic acid. In this paper, biobased citric acid was chosen to prepare SAP in order to confirm the possibility of ground-up synthesis for biobased SAP, due to its cost-effectiveness, non-toxicity and multifunctionality that can induce random 3D-network structure. With suitable diol counterpart and neutralization of CA, the absorbency was enhanced. To further develop synthesized SAP and compensate the absence of secondary crosslinking, hexamethylene diisocyanate (HDI) was used to stabilize 3D-network structure. The maximum absorbency of CA-based SAP was around 2200%.