Itaconic‐acid‐based superabsorbent polymer with high gel strength and biocompatibility

An elaborate surface‐crosslinking method was introduced to enhance the low absorbency under load (AUL) and liquid permeability of itaconic‐acid‐based superabsorbent polymer (SAP). The effects of the surface‐crosslinking reaction parameters of the absorption properties of the SAP were investigated. An increase in the content of distilled water and 1,4‐butanediol used as the surface‐crosslinking solution improved the AUL and liquid permeability of the SAP, whereas an increase in the distilled water content resulted in a sharp decrease in the centrifuge retention capacity (CRC) of the SAP. Therefore, controlling the content of 1,4‐butanediol is an effective strategy to improve the AUL while maintaining the CRC of the SAP to some extent. Increasing the surface‐crosslinking temperature tends to decrease the CRC of the SAP. The AUL of the SAP is the highest at a reaction temperature of 160 °C. As a result, the SAP prepared under optimal surface‐crosslinking conditions showed a CRC, AUL and liquid permeability of 36.0, 27.2 g g–1 and 80 s, respectively. The cell viability and cytotoxicity of the SAP on human dermal fibroblasts were confirmed using a live/dead assay and the adapted method from the ISO 10993‐5 protocol. These investigations suggested that itaconic‐acid‐based SAPs could be potential materials for diaper products. © 2022 Society of Industrial Chemistry. The low gel strength of itaconic‐acid‐based superabsorbent polymer (SAP) was improved through a sophisticated surface‐crosslinking method. The absorption performance of the surface‐crosslinked SAP was similar to the recommended value of commercial SAP, and these results show the potential of bio‐based SAP to replace commercial SAP.