Acylation of agricultural protein biomass yields biodegradable superabsorbent plastics

Superabsorbent polymers (SAP) are widely used in hygiene and medical products but are typically petroleum-derived. This work shows that sustainable, biodegradable SAPs can be produced by acylating potato protein concentrate (PPC), an agricultural side-stream, with the non-toxic dianhydride EDTAD. Acylated PPC achieved a water swelling capacity of ~2400% (~24 g g−1), ten times higher than untreated PPC. Acylation was also carried out directly on potato fruit juice (PFJ), upstream of the industrial precipitation process. Implementing acylation at the PFJ stage could avoid energy-intensive drying to PPC and save an estimated ~320,000 tons CO2 annually. The acylated PPC exhibited biodegradation and resistance to mould growth. These biodegradable SAPs from PPC could enable environmentally friendly disposable products such as diapers and sanitary pads.

Antonio J. Capezza, Faraz Muneer, Thomas Prade, William R. Newson, Oisik Das, Malin Lundman, Richard T. Olsson, Mikael S. Hedenqvist, Eva Johansson