Non-destructive evaluation of the curing of a polybenzoxazine nanocomposite blend for space applications using fluorescence spectroscopy and predictive mechanical modelling

In this study, we employ fluorescence spectroscopy to monitor the curing process of a novel polybenzoxazine (PBZ) resin blend containing a polyhedral oligomeric silsesquioxane (POSS) reagent in a non-destructive way and compare it with the differential scanning calorimetry data. Our resin blend has been carefully selected for study on the International Space Station in 2024 as part of the Euro Materials Ageing 1 Programme (AO-2020-EMA) supported by the European Space Agency (ESA) and the French Space Agency (CNES). Computational simulations of PBZ-POSS blend composites are investigated to determine their effective mechanical responses based on constituent micro-stresses with periodic boundary conditions and continuum-based analytical micromechanical models. Further investigations are focused on the development of different representative volume element models, including periodic, non-periodic, and overlap inclusions, and the comparison with experimental data. Fluorescence spectroscopy and computational and analytical methods can offer a non-destructive approach to gaining insights into polymerisation processes and effective mechanical responses.