Preparation, Rheological Behavior, and Application of PAA ‐ SS Composite Hydrogels

ABSTRACT

Poly(acrylic acid) (PAA)‐based hydrogel electrolytes possess favorable ionic transport properties but relatively limited network stability. This study aims to regulate the PAA hydrogel network by introducing sulfonated starch (SS) and to clarify the relationship between structural evolution, mechanical behavior, and electrochemical performance. The incorporation of SS promoted network densification and enhanced intermolecular interactions, resulting in an elastic‐dominated viscoelastic response over a broad frequency range. With increasing SS content, the tensile strength increased from 18 to 43 kPa and the toughness from 63 to 194 kJ·m ⁻³ , while an elongation at break of approximately 850% was maintained. SS incorporation also improved the swelling and water‐retention behavior of the hydrogels. The ionic conductivity reached a maximum of approximately 117.3 mS·cm ⁻¹ for PAA‐SS‐7.5, whereas PAA‐SS‐10 exhibited the best long‐term electrochemical stability, with a discharge duration of approximately 42 h at 1 mA·cm ⁻² . These results demonstrate that SS incorporation provides an effective strategy for balancing mechanical stability, swelling and water‐retention behavior, ion transport, and electrochemical performance in PAA‐based hydrogel electrolytes.