Applying SEM‐Based X‐ray Microtomography to Observe Self‐Healing in Solvent Encapsulated Thermoplastic Materials

Abstract In this work X‐ray microtomography was used to observe fracture and healing processes in a liquid‐based self‐healing thermoplastic material. The method was able to produce data of sufficient resolution (<10 μm) to observe ∼60 μm microcapsules containing solvent within a polymeric material and in particular their behavior around a crack zone after fracture and healing. The reconstructed data showed the distribution of filled and several empty microcapsules within the matrix material. Additional color segmentation and 3D rendering of the data unambiguously demonstrated a large concentration of ruptured microcapsules near the fracture surfaces, covering ∼75 μm span on both sides of the crack. A close investigation of the crack area confirmed the presence of healed and non‐healed regions. Further analysis of the segmented data allowed a quantitative determination of the release of the encapsulated solvent.