Preparation of γ-aminopropyltriethoxysilane cross-linked poly(aspartic acid) superabsorbent hydrogels without organic solvent

Poly(aspartic acid) (PASP) hydrogel is a type of biodegradable and biocompatible polymer with high water absorbing ability. Traditionally, the production of PASP hydrogel is expensive, complex, environmentally unfriendly, and consumes a large amount of organic solvents, e.g. dimethylformamide or dimethylsulfoxide. This study introduces a one-step synthesis of PASP resin, in which the organic phase was replaced by distilled water and γ-aminopropyltriethoxysilane was used as the cross-linker. Absorbent ability and characteristics were determined by swelling ratio, FTIR, (13)C SSNMR, and SEM. In vitro cytotoxicity evaluation and animal skin irritation tests showed the hydrogel has body-friendly properties. Preparing PASP hydrogel in aqueous solution is promising and finds its use in many applications.