The replacement of fossil-derived (meth)acrylic monomers represents a central challenge in the development of sustainable polymeric materials, particularly in additive manufacturing technologies based on photopolymerization. In this context, itaconic acid, a biobased platform molecule produced via fermentation, has emerged as a highly promising candidate due to its α,β-unsaturated structure, enabling radical polymerization, and its bifunctional nature, which allows for versatile molecular design. In our early work, [1] we first demonstrated the feasibility of employing itaconic acid derivatives as reactive building blocks for photocurable polymer systems, establishing their potential as sustainable alternatives to conventional (meth)acrylates. This study provided key insights into the reactivity of itaconate functionalities, their compatibility with radical photopolymerization, and their integration into crosslinked polymer networks, thus defining the fundamental principles for their use in additive manufacturing.

Building on this foundation, subsequent studies expanded the structural complexity and application scope of itaconate-based materials. In particular, the design of functional macromers, including tailored polyesters and branched polycaprolactone architectures, [2] enabled the formulation of fully liquid, highly biobased resins suitable for vat photopolymerization. These systems achieved biobased contents up to ~97% while maintaining excellent printability and mechanical performance across a broad range of properties, demonstrating the viability of replacing fossil-based monomers without compromising functionality.

Further developments explored the role of itaconic acid in tuning network architecture and material properties through its incorporation into advanced resin formulations. [3] These studies highlighted how the unique chemical structure of itaconates can be exploited to control crosslinking density, segmental mobility, and ultimately the mechanical response of the resulting thermosets, enabling performance comparable to, or exceeding, that of conventional (meth)acrylate-based systems.

In parallel, alternative polymer chemistries incorporating itaconic acid have been investigated, including poly(ester-amide)s [4] and isocyanate-free urethane-based systems, [5] further demonstrating the versatility of this platform across different polymer classes and processing conditions. These approaches enable access to materials with tunable mechanical properties, improved sustainability profiles, and compatibility with high-resolution additive manufacturing techniques.

More recently, the scope of itaconic acid chemistry has been extended beyond photocurable systems toward circular polymer concepts. In particular, the development of depolymerization and repolymerization strategies for commodity polymers such as PET [6] demonstrates how itaconate-based chemistries can contribute not only to the replacement of fossil-derived monomers but also to the implementation of closed-loop material cycles. This approach establishes a direct link between sustainable monomer design and polymer circularity, opening new opportunities for integrating additive manufacturing with recycling and upcycling strategies.

Overall, this body of work establishes itaconic acid as more than a simple alternative to (meth)acrylates: it represents a unifying chemical platform enabling the design of next-generation polymer systems for additive manufacturing, combining sustainability, structural tunability, high performance, and circularity within a single framework.

References

1- M. Maturi, C. Pulignani, E. Locatelli, V. Vetri Buratti, S. Tortorella, L. Sambri, M. Comes Franchini Green Chem. 2020, 22, 6212.

2- C. Spanu, E. Locatelli, L. Sambri, M. Comes Franchini, M. Maturi ACS Appl. Polym. Mater. 2024, 6, 2417.

3- M. Maturi, C. Spanu, E. Maccaferri, E. Locatelli, T. Benelli, L. Mazzocchetti, L. Sambri, L. Giorgini, M.C. Franchini ACS Sustain. Chem. Eng. 2023, 11, 17285.

4- V. Vetri Buratti, A. Sanz De Leon, M. Maturi, L. Sambri, S.I. Molina, M. Comes Franchini, Macromolecules 2022 55, 3087.

5- R. Carmenini, C. Spanu, E. Locatelli, L. Sambri, M. Comes Franchini, M. Maturi Progress in Additive Manufacturing 2024, 9, 2499.

6- R. Carmenini, A. Sanz de León, T. Benelli, L. Giorgini, M.C. Franchini, S.I. Molina, M. Maturi Green Chem. 2025, 27, 12830.

Acknowledgments

All the authors acknowledge financial support from the Spanish Ministry of Science, Innovation, and Universities MICIU/AEI/10.13039/ 501100011033 (Project PID2023-151632OB-C22) and from FEDER, EU.