Public Thesis Defense of Quentin PAPELOER - IMCN
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3D-Printed Hierarchically-Porous Objects from Controlled Phase Separation in Semicrystalline PLA/PEG Blends by Quentin PAPELOER -
Thursday, 11 September 2025 at 2:30 p.m. - Room SUD01 - Place Croix du Sud - 1348 Louvain-la-Neuve
This thesis presents a solvent-free strategy for fabricating hierarchically porous biomaterials based on poly(L-lactic acid) (PLA) and polyethylene glycol (PEG).
The approach exploits crystallization-induced phase separation in PLA/PEG blends, followed by PEG extraction, to generate tunable microporosity and multi-scale porous architectures. The influence of PEG content and molar mass on the crystallization kinetics, spherulitic morphology and phase distribution of PLA/PEG blends was systematically investigated using differential scanning calorimetry (DSC and flash DSC), polarized optical microscopy (POM), and X-ray diffraction (XRD). An experimental phase diagram of the PLA/PEG system was constructed using flash DSC, based on the distinct thermal transitions observed across different blend compositions and isothermal temperatures. This diagram enabled the prediction of PEG localization and the resulting microporosity (<50 µm) after selective extraction, which, combined with macroporosity introduced through fused deposition modeling (FDM), resulted in a hierarchical porous architecture. Micro-computed tomography (µCT) and scanning electron microscopy (SEM) confirmed the presence of a continuous microporous network across both cast films and 3D-printed structures. Mechanical testing revealed that macroporosity significantly reduced performance, whereas microporosity had a lesser impact, as residual PEG, after extraction, preserved flexibility. Crystallization-driven phase separation provides a versatile strategy to tailor the morphology and mechanical properties of hierarchically porous systems.
This approach demonstrates the fabrication of porous structures with complex geometries using readily available materials and solvent-free processing methods. Such a strategy enables on-site production of patient-specific implants and may significantly accelerate treatment timelines in the context of personalized medicine.
Jury members
- Prof. Alain M. Jonas (UCLouvain) (Supervisor)
- Prof. Sophie Demoustier-Champagne (UCLouvain) (Supervisor)
- Prof. Arnaud Delcorte (UCLouvain) (Chairperson)
- Prof. Charles-André Fustin (UCLouvain) (Secretary)
- Prof. Evelyne Van Ruymbeke (UCLouvain)
- Prof. Jannick Duchet-Rumeau (INSA Lyon)
- Prof. Bart Goderis (KULeuven)