Additive manufacturing technologies have revolutionized manufacturing processes by enabling unprecedented design freedom, material efficiency, and the direct fabrication of complex, customized components. Among the different techniques, material extrusion (ME) and vat photopolymerization (VP) are currently the most widely adopted. However, both approaches still rely predominantly on petroleum-derived polymers when high mechanical performance and structural integrity are required. In structural applications, ME typically employs thermoplastics such as ABS, PA, or PETG, while VP is mainly based on (meth)acrylate-derived monomers. This strong dependence on fossil-based feedstocks significantly limits the sustainability of these technologies.

In this context, our research focuses on developing more sustainable materials for additive manufacturing while maintaining competitive performance. To this end, we follow multiple complementary strategies. One approach involves the partial replacement of the polymer matrix with agro-industrial residues or their derivatives (e.g., nanocellulose), prioritizing locally sourced biomass such as cork, olive pruning waste, or algae residues to minimize the carbon footprint. This strategy can simultaneously enhance sustainability and reduce material costs. A key aspect is not only achieving homogeneous dispersion within the matrix, but also ensuring adequate interfacial compatibility in order to preserve mechanical properties [1,2,3]. In VP systems, we also explore the replacement of conventional acrylic monomers with bio-based alternatives, such as itaconic acid as well as the use of recycled monomers obtained from polymer waste (e.g., polyesters) through depolymerization–repolymerization routes [4,5]. These approaches, either independently or in combination, enable the development of printable materials that, in many cases, exhibit properties comparable to those of commercially available counterparts.

References

1- A. Sanz de León, F. Núñez Gálvez, D. Moreno Sánchez, N. Fernández Delgado, S.I. Molina ACS Appl. Polym. Mater. 2022, 4, 1225.

2- M. Maturi, C. Spanu, N. Fernández Delgado, S.I. Molina, M. Comes Franchini, E. Locatelli, A. Sanz de León Addit. Manuf. 2022, 61, 103342.

3- P. Burgos Pintos, P. Marzo Gago, N. Fernández Delgado, M. Herrera, A. Sanz de León, S.I. Molina Virtual Phys. Protot. 2024, 19, e2386106.

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

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

Acknowledgments

Financial support from the Spanish Ministry of Science, Innovation, and Universities (Project PID2023-151632OB-C22), FEDER-EU, and research group INNANOMAT (ref. TEP-946) is gratefully acknowledged.