Plasticization of a corn protein for Additive Manufacturing

Additive manufacturing using fused filament fabrication (FFF) to produce biodegradable and edible parts from natural biopolymers opens up new possibilities for applications in the food industry and in the pharmaceutical and biomedical fields.

During this process, the thermoplastic material is extruded through a nozzle and deposited layer by layer, following a three-dimensional digital model of the part to be printed. Cohesion between the deposited layers requires their adhesion, achieved through the spreading of the extruded filament and the interdiffusion of polymer macromolecules at their interface, thereby ensuring the mechanical integrity of the printed object. Through a detailed literature review of FA-DFF and the establishment of material specifications for this process, the processing window for a material based on a natural biopolymer can be defined, thereby giving 3D-printed parts functionalities unattainable with synthetic polymers, particularly in terms of edibility and (bio)resorbability.

Through a review of the state of the art, zein—a maize storage protein co-produced in starch processing—will be evaluated as a candidate for implementation via FA-DFF, by directly extruding this plasticized material into the material deposition nozzle without first producing a spool of calibrated filament. In this way, a reduction in the thermal aggregation of this protein is expected, in order to ensure its deposition in a fluid molten state, and its thermomechanical and rheological properties, as well as its adhesion capabilities in the molten state, will be measured to verify its compatibility with the specifications of the targeted process.

This article thus presents an innovative and effective approach to producing 3D-printed parts with controlled structures through additive manufacturing, enabling the targeted and controlled release of molecules of interest.