Epsilon Archive for Student Projects

Abstract

This study explores the development of protein-based superabsorbent materials derived from green agricultural biomass, focusing on the leaves of winter wheat, lucerne, and sugar beet. These biomasses, either underutilized or considered by-products, were processed at the plant protein factory at the Swedish University of Agricultural Sciences in Alnarp to extract green juice, which served as the primary protein source. Through chemical modification using ethylenediaminetetraacetic dianhydride (EDTAD) and crosslinking with genipin, the proteins were transformed into materials with enhanced water absorption and retention capacities. A series of analytical methods, including free swelling capacity (FSC) testing, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC), were used to assess the structural, thermal, and functional properties of the modified materials. The results revealed that functionalised and crosslinked sugar beet proteins without autoclaving (+EDTAD+Genipin 0 min) exhibited the highest FSC (~28 g/g), followed by winter wheat (~10.5 g/g) under the same conditions, while lucerne reached its highest FSC (~7 g/g) after acylation without crosslinking and with 20 min of autoclaving (+EDTAD – Genipin 20 min), likely due to differences in amino acid composition and structural stability. Chemical modifications with +EDTAD +Genipin 0 min autoclaving improved thermal stability according to TGA.

Overall, the results validate the feasibility of using functionalized leaf protein from green agricultural biomass—particularly sugar beet leaves as a foundation for developing high-performance superabsorbent materials. This highlights a step toward replacing petroleum-based polymers with sustainable, bio-based alternatives.