Sustainable itaconamide monomers from amino acids for vat photopolymerization 3D printing

Abstract

Vat photopolymerization (VP) is a rapidly growing additive manufacturing technology (3D-printing), yet its reliance on fossil-derived and potentially hazardous acrylate resins presents a significant sustainability challenge. Although itaconic acid has emerged as a promising bio-based platform chemical, current synthetic strategies to functionalize it often involve toxic intermediates and energy-intensive processes. This work reports a sustainable route for the synthesis of a novel class of itaconamide monomers derived from essential amino acids (alanine, valine, isoleucine, and phenylalanine) via the direct, solvent-minimised ring-opening of itaconic anhydride. This approach avoids chlorinated reagents and activation steps, aligning with green chemistry principles. The monomers were incorporated into photocurable formulations (up to 40 mol%), demonstrating highly tunable mechanical properties: aliphatic derivatives acted as efficient plasticizers, increasing elongation at break by up to 385%, while phenylalanine moieties provided network reinforcement via π–π interactions. Thermal analysis confirmed stable glass transition temperatures combined with enhanced char yields. Crucially, a quantitative sustainability assessment yielded a Sustainable Formulation Score (SFS) of up to 51.8, significantly outperforming current state of the art bio-based resins. The successful fabrication of high-resolution 3D printed objects confirms these materials as viable, high-performance, and eco-friendly candidates for VP.