Reactive extrusion of zein with glyoxal and polyethylene maleic anhydride

Authors: Selling, Gordon; Utt, Kelly

Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 1/15/2017
Publication Date: 4/2/2017
Citation: Selling, G.W., Utt, K.D. 2017. Reactive extrusion of zein with glyoxal and polyethylene maleic anhydride [abstract]. American Chemical Society National Meeting and Exposition, April 2-6, 2017, San Francisco, CA.

Interpretive Summary: This research provides a method to modify corn protein (zein), which is a major component in the co-products of bioethanol production, into a material that has improved solvent resistance. One of the main drawbacks that zein based articles have is their sensitivity to solvents. On exposure to certain solvents, such as ethanol, zein based articles will deform to the point that they may dissolve. We have found a reagent that will modify zein to provide improved solvent resistance. This reagent also improves the strength of zein articles. Most importantly, the modification reaction can take place in an extruder (used through the plastics industry). This is important as by using an extruder, there are no solvents (and no solvent waste) and the process can be more easily transferred to industry. This information will be beneficial to manufacturers involved in the production of ethanol from corn as well as those companies interested in producing biobased (zein) articles.

Technical Abstract: In order for zein, a potentially significant co-product of the bio-ethanol industry, to be used in new markets, improved zein based products are needed. These products need to be produced by the most economical means possible, and extrusion techniques meet these requirements. It has been shown that the processing window for zein on an extruder is quite large, up to 160°C. This suggests that various reactive reagents can be employed to provide a modified zein protein using reactive extrusion techniques. We will report on our efforts to modify zein using either glyoxal or polyethylene maleic anhydride (PEMA) in solution and in the melt state. As PEMA is polymeric, it is orders of magnitude safer than other crosslinking technologies. The zein modification was undertaken in melt batch processes using reactive extrusion. Final melt processed articles were produced by compression molding and by injection molding. The articles produced had improved physical properties and improved solvent resistance.