28 Jul PhD Thesis Defense: Sihem Zaidi Advances Sustainable Processing of Resin Systems for Structural Composites
On 10 July 2026, Sihem Zaidi successfully defended her PhD thesis, «Investigation of the Processability and Thermal Stability of Sustainable Resins as Durable Matrices for Structural Composites», at the University of Girona (UdG).
The thesis was supervised by Dr. Jordi Farjas Silva and Dr. Daniel Sánchez Rodríguez
Advancing the Processing of Sustainable Composite Materials
Fibre-reinforced polymer (FRP) composites play a key role in lightweight structural applications, where the curing process of the resin matrix is critical to achieving optimal mechanical performance, durability and manufacturing efficiency. As industry increasingly adopts bio-based and recyclable resin systems, new scientific approaches are required to better understand and control their complex curing behaviour.
Sihem Zaidi’s doctoral research addresses these challenges by developing predictive methodologies that combine advanced thermal analysis with isoconversional kinetic modelling. Her work provides reliable tools for designing efficient curing cycles while minimizing energy consumption and ensuring high-quality composite manufacturing.
Main Scientific Contributions
The research has delivered several important advances in the field of composite processing, including:
- A comprehensive characterization of the curing kinetics, rheological behaviour, thermo-mechanical properties and thermal degradation of a newly synthesized bio-based epoxy resin derived from vanillin.
- The development of a predictive processing framework integrating advanced thermal analysis and isoconversional kinetic modelling to optimize curing conditions.
- Novel processing tools for commercial epoxy systems that incorporate realistic industrial heating ramps followed by isothermal curing, enabling more efficient manufacturing strategies.
- An in-depth investigation of the polymerization behaviour and thermal stability of a fully recyclable thermoplastic resin, highlighting the influence of the initiator on induction periods and reaction kinetics.
- Extensive experimental validation of the proposed processability charts through complementary thermal, rheological and mechanical characterization, confirming their predictive capability and robustness.
Scientific Publications
During her PhD, Dr. Zaidi produced an outstanding scientific output, publishing in leading international journals in the fields of polymer science, composite materials and thermal analysis. Her work has contributed to advancing the understanding of sustainable thermoset and thermoplastic processing, predictive cure modelling, and recyclable polymer systems.
Published articles
- Sanchez-Rodriguez, D., Zaidi, S., Jahani, Y., Ruiz de Luzuriaga, A., Rekondo, A., Maimi, P., Farjas, J., & Costa, J. (2023). Processability and reprocessability maps for vitrimers considering thermal degradation and thermal gradients. Polymer Degradation and Stability, 217, 110543.
https://doi.org/10.1016/j.polymdegradstab.2023.110543 - Zaidi, S., Thakur, S., Sanchez-Rodriguez, D., Verdejo, R., Farjas, J., & Costa, J. (2024). Optimal processing conditions of a bio-based epoxy synthesized from vanillyl alcohol. Polymer Degradation and Stability, 223, 110743.
https://doi.org/10.1016/j.polymdegradstab.2024.110743 - Sanchez-Rodriguez, D., Zaidi, S., Carreras, L., Ruiz de Luzuriaga, A., Rekondo, A., Costa, J., & Farjas, J. (2024). Time-temperature-transformation diagrams from isoconversional kinetic analyses applied to the processing and reprocessing of vitrimers. Thermochimica Acta, 736, 179744.
https://doi.org/10.1016/j.thermoacta.2024.179744
- Gkertzos, P., Kotzakolios, A., Katsidimas, I., Zaidi, S., Sanchez-Rodriguez, D., Costa, J., & Kostopoulos, V. (2025). Comparative fitting methodology of cure kinetics models based on differential scanning calorimetry. Journal of Composite Materials, 59(1), 75–98.
https://doi.org/10.1177/00219983241295816 - Farjas, J., Sanchez-Rodriguez, D., Zaidi, S., Carstea, D.-R.-C., Abd Elfatah, A. M. S., Rotaru, A., & Costa, J. (2025). Analytical prediction of the thermal overheating in curing thick layers of fibre-reinforced thermosets. Composites Part A: Applied Science and Manufacturing, 193, 108815.
https://doi.org/10.1016/j.compositesa.2025.108815 - Zaidi, S., Sanchez-Rodriguez, D., Farjas, J., Verdejo, R., López-Manchado, M. A., Trias, D., & Costa, J. (2025). Processability map of a recyclable thermoplastic for structural applications: Kinetics of induction period. ACS Omega.
https://doi.org/10.1021/acsomega.5c10999 - Zaidi, S., Sanchez-Rodriguez, D., Saleh, A. M., Farjas, J., Spencer, P., & Costa, J. (2026). Incorporating the Heating Stage into Processability Maps for Epoxy Curing Optimization. ACS Omega.
