Title: UV-curable methacrylated zein inks: Tailoring biopolymer-based materials for 3D printing
Authors: Derniza-Elena Cozorici a, Erika Blanzeanu a, Ionut-Cristian Radu a, Marian Nicolae Verziu a, Cristina Stavarache a, Minodora Marin a, Rafael Luque a b, Catalin Zaharia a, Horia Iovua
Affiliations: a Advanced Polymer Materials Group, Faculty of Chemical Engineering and Biotechnology, National University of Science and Technology POLITEHNICA Bucharest, 1-7 Gh. Polizu Street, Bucharest 011061, Romania b Universidad ECOTEC, Km. 13.5 Samborondón, Samborondón EC092302, Ecuador
As 3D printing continues to evolve, the development of new printable materials is crucial for advancing a wide range of applications in this field. Zein, a by-product of corn processing, is a biodegradable biopolymer and sustainable alternative to synthetic polymers. It has gained attention for its biocompatibility and versatility in various applications, including 3D printing.
This research study explores the development of a zein-based ink for pneumatically driven extrusion 3D printing. It investigates two approaches to modifying zein through methacrylation to achieve a UV-crosslinkable ink formulation. The first route involves a two-step process: initially, hydroxyl groups are introduced onto the zein backbone through esterification, followed by methacrylation of these hydroxyl groups using methacrylic acid. This approach is designed to enhance the reactivity of zein and improve the efficiency of the methacrylation process. The second route streamlines the process by using a single-step methacrylation with the monomer 2-hydroxypropyl methacrylate. Furthermore, the ink formulation optimization process involves iterative adjustments, exploring the blending of methacrylated zein with other biopolymers to enhance the ink's properties.
This study includes the validation of zein methacrylation using Fourier Transform Infrared (FTIR) and Proton Nuclear Magnetic Resonance (¹H NMR) spectroscopy, analysis of the ink’s shear-thinning behavior through rheological testing, evaluation of its 3D printability, and photo-crosslinking of the printed constructs.
These findings contribute to the limited research on zein-based 3D printing, highlighting its potential for sustainable manufacturing and soft tissue engineering while addressing the need for environmentally friendly ink formulations.