ABSTRACT Ball milling‐induced polymer chain scission is increasingly explored for applications relevant to synthesis and recycling. Kinetic studies have improved our understanding of how milling and polymer parameters influence chain scission. However, many of these investigations rely on model polymers and are restricted to small sample masses, limiting their relevance to common plastic materials. Here, the chain scission kinetics of polystyrene under planetary ball‐milling conditions are examined across an extended polymer mass range, using commercial pellets alongside waste‐derived foams and lids to represent both plastic feedstocks and end‐of‐life products. Large variations in degradation rates are observed when samples with different particle sizes are used. In contrast, when samples are prepared to comparable particle sizes, degradation rate constants decrease systematically with increasing polymer mass and with minimal variation across sample types. Furthermore, molecular weight evolution trends obtained at different masses converge when analyzed as a function of mechanical energy dose estimated from a kinematic model. By extending mechanochemical kinetic analysis beyond model polymers and small sample masses, this work provides a foundation for studying chain scission in real‐world plastic materials relevant to emerging applications.
Cha et al. (Tue,) studied this question.