Plasma based superabsorbent materials modulated through chemical cross-linking

Abstract

Superabsorbent materials, showing water absorption higher than 1000 wt%, are traditionally formulated on acrylic derivatives, which are expensive and with low biodegradability. The massive use of non-biodegradable plastic materials has caused a serious environmental impact which especially affects oceans and seas. Thus, their replacement by bioplastics results interesting, for which one of the main challenges is the achievement of adequate mechanical properties. This work aims to improve those properties for a superabsorbent bioplastic based on porcine plasma protein, and different amounts of glutaraldehyde as cross-linking agent. When glutaraldehyde is added either directly in the protein-plasticizer blend (0.1–0.2 wt%) or through immersion of the injection-molded material in an aqueous solution of the cross-linker (0.005 wt%) resulted in superabsorbent materials that maintain their integrity after swelling. Soluble material loss decreases in a greater extent when glutaraldehyde was added through immersion. These results highlight the potential of a by-product of the meat industry as raw material of biodegradable superabsorbent materials with improved mechanical properties, which could find applications in agriculture or horticulture.