Modeling stress-enhanced photo-degradation in amorphous glassy polymers

The emergence of renewable, degradable polymers in everyday applications necessitates the prediction of their mechanical behavior during service. In a recent contribution, Alkhoury et al. (2024) characterized changes in microstructural and mechanical behavior resulting from stress-enhanced photo-degradation of cellulose acetate, a renewable and degradable glassy amorphous polymer used in various consumer products. In this work, we complement the existing set of experiments and develop a thermodynamically consistent constitutive model informed by both micro- and macro-scale information. The outcome of this work enables the prediction of the mechanical behavior of photo-degrading glassy amorphous polymers while subjected to stresses. This can help engineers design sustainable devices while ensuring product integrity.