3D fluorescent mapping of invisible molecular damage after cavitation in hydrogen exposed elastomers

Xavier P Morelle (1, 2) , Gabriel E Sanoja (2) , Sylvie Castagnet (3) , Costantino Creton (2)

1 ESPCI Paris - Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris
2 SIMM - Sciences et Ingénierie de la Matière Molle (UMR 7615)
3 ENDO - ENDOmmagement et durabilité [Institut Pprime]

Elastomers saturated with gas at high pressure suffer from cavity nucleation, inflation, and deflation upon rapid or explosive decompression. Although this process often results in undetectable changes in appearance, it causes internal damage, hampers functionality (e.g., permeability), and shortens lifetime. Here, we tag a model poly(ethyl acrylate) elastomer with extended anthracene-maleimide adducts that fluoresce upon polymer chain scission, and map in 3D the internal damage present after a cycle of gas saturation and rapid decompression. Interestingly, we observe that each cavity observable during the decompression results in a damaged region, the shape of which reveals a fracture locus of randomly oriented penny-shape cracks (i.e., with a flower-like morphology) that contain crack arrest lines. Thus, cavity growth likely proceeds discontinuously (i.e., non steadily) through the stable and unstable fracture of numerous 2D crack planes. This non-destructive methodology to visualize in 3D molecular damage in polymer networks is novel and serves to understand how fracture occurs under complex 3D loads, predict mechanical aging of pristine looking elastomers, and holds potential to optimize cavitation-resistant materials.

Mots clés: Mechanochemistry; Cavitation; Fracture; Decompression Failure; Hydrogen; Elastomer

Domaines: Polymères; Mécanique des matériaux [physics.class-ph]

Xavier P Morelle, Gabriel E Sanoja, Sylvie Castagnet, Costantino Creton. 3D fluorescent mapping of invisible molecular damage after cavitation in hydrogen exposed elastomers. Soft Matter, 2021, 17 (16), pp.4266-4274. ⟨10.1039/D1SM00325A⟩. ⟨hal-03256540⟩