Extrusion of Porous Protein-Based Polymers and Their Liquid Absorption Characteristics

Abstract

The production of porous wheat gluten (WG) absorbent materials by means of extrusion processing is presented for the future development of sustainable superabsorbent polymers (SAPs). Different temperatures, formulations, and WG compositions were used to determine a useful protocol that provides the best combination of porosity and water swelling properties. The most optimal formulation was based on 50 wt.% WG in water that was processed at 80 °C as a mixture, which provided a porous core structure with a denser outer shell. As a green foaming agent, food-grade sodium bicarbonate was added during the processing, which allowed the formation of a more open porous material. This extruded WG material was able to swell 280% in water and, due to the open-cell structure, 28% with non-polar limonene. The results are paving the way towards production of porous bio macromolecular structures with high polar/non-polar liquid uptake, using extrusion as a solvent free and energy efficient production technique without toxic reagents.

Sustainable Wheat Protein Biofoams: Dry Upscalable Extrusion at Low Temperature

“…The 70/30 gluten/glycerol weight ratio was selected based on previous work, which showed that this composition yielded a combination of mechanically flexible and ductile films and good extrudability . When using the foaming agents SBC and ABC, 2.5 g (5 wt %) of these were added during the mixing, and the WG content was lowered to 32.5 g, following the previous optimization work with SBC . The mixture was processed with two different types of equipment: I, a conical fully intermeshing and corotating double-screw microcompounder (DSM Xplore 5 cc, The Netherlands); II, a single screw extruder (Brabender Do-Corder C3, Germany).…”

“…The strong cohesive properties and viscoelastic nature of WG , make it a potential material option for producing foams through conventional extrusion. − The production of WG foams from aqueous solutions through lyophilization has been reported ,, and also using other techniques like microwave heating. ,, Moreover, WG foams with a range of built-in features have been made, including improved electric and thermal conductance, ,, superabsorbency, ,− and microbial resistance. , …”

“…During extrusion, the protein is subjected to several restructuring mechanisms involving denaturation of the protein and the formation of new covalent and noncovalent bonds . The rheological properties of the materials during processing, and the mechanical properties of the produced product can be tailored using different contents of plasticizer, for example, glycerol. ,− To achieve porosity during processing, chemical blowing agents (CBA) are often used to produce extruded foams. A popular CBA is sodium bicarbonate (SBC), a leavening agent used in the bakery industry, which has recently been used to extrude expanded/porous wheat gluten materials .…”

Valorization of Starch to Biobased Materials: A Review

“…The change in the extrusion processing parameters using the best ratios of wheat starch/glycerol/gluten/sodium bicarbonate (100/46/25/1) resulted in a higher and more stable expansion (9.1) at a screw speed and input rate of 300 rpm and 21 kg/h, respectively. In general, a feed with a water content of 15–18% is regarded best for producing foams with the maximum expansion ratio [ 277 ]. Extrusion for biofoam manufacturing will necessitate further experimental and modeling studies to improve theoretical knowledge and technical processes, as it is a necessary operation in practically all industrial applications.…”

The need for fully bio-based facemasks to counter coronavirus outbreaks: A perspective

“…Gluten, like most commodity polymers (e.g. polyethylene and polypropylene), can be processed using established methods of compression moulding, injection moulding, extrusion and thermoforming to create a variety of shapes that include thin films and complex geometries (Capezza et al, 2020b;Rasel et al, 2016;Redl et al, 1999). Furthermore, gluten can also be electrospun into nanofibre membranes.…”