In-Situ Multi-Scale Characterization of Bio-Based Non-Isocyanate Polyurethane (NIPU) Foams Using X-ray Microtomography

This study explores bio-based Non-Isocyanate Polyurethane (NIPU) foams derived from lignin as a sustainable alternative to conventional polyurethane. Using synchrotron X-ray microtomography at ESRF, we will perform in-situ multi-scale characterization to link microstructure to mechanical performance. Three key scales—struts (≈20 µm), cellular structure (1–2 mm), and multi-layer composite (≈10 mm)—will be analyzed under compressive loading. Various formulations will be tested, modifying lignin type, cross-linkers, and foaming agents to optimize structural and mechanical properties. High-resolution imaging (2–6 µm voxel size) will capture microstructural changes, aiding in the development of durable, recyclable NIPU foams. Findings will support industrial adoption of greener polyurethane alternatives while enhancing material design for automotive applications.