Ionic-bonded superabsorbent polymers and their surface-crosslinking using modified silica

Abstract

The purpose of this study is to improve the low absorbency under load and the permeability of a superabsorbent polymer (SAP)-based on itaconic acid by introducing a polycationic salt into the core-SAP to form ionic bonds as well as by adding modified silica to the surface-crosslinked SAP. The core-SAP was synthesized by aqueous polymerization using itaconic acid, vinyl sulfonic acid, and tetra (ethylene glycol) diacrylate. The absorbency under loading of the core-SAP was improved using aluminum sulfate and zirconium sulfate as polycationic salts. The surface-crosslinked core-SAP with the modified silica showed increased permeability.