Practical Improvement of SAP Hydrogel Properties via Facile Tunable Cross-linking of the Particles Surface

ABSTRACT

To improve gel toughness, surface cross-linking of partiallyneutralized acrylic acid based superabsorbent polymers (superabsorbent polymers, prepared by solution polymerization) was performed by diethylene glycol diglycidyl ether. Considering effective factors (treatment solution, surface cross-linker content, post-treatment temperature, and duration), a two-step surface modification procedure was performed on dried superabsorbent polymers particles. Attenuated total reflection–Fourier transform infrared spectroscopy has proved chemical cross-linking reaction. Mechanical properties have also been investigated. Besides, the modified rubber elasticity theory and Flory–Rehner equations have been used to investigate how they work in core–shell-like structure. The optimum condition provides at least a 100% raise in gel strength and appropriate absorbency.

GRAPHICAL ABSTRACT

KEYWORDS:

• Diethylene glycol diglycidyl ether
• hydrogel swelling
• poly(acrylic acid)
• superabsorbent
• surface cross-linking