Kinetic migration of PBS and PBSA biopolymers prepared by cast film extrusion and biaxial stretching: A combined experimental and modeling approach

AbstractThe kinetic migration of poly(butylene succinate) (PBS) and poly(butylene succinate‐co‐adipate) (PBSA) biopolymers, prepared by cast film extrusion (thin film) and biaxial stretching (biaxially oriented [BO] film) techniques, were investigated based on experimental and mathematical modeling. MATLAB coding was used to fit the migration data to a diffusion model. BO films significantly reduced the migration rate compared with thin films, with reductions of 29% and 41% for BO‐PBS and BO‐PBSA, respectively, due to the increased degree of molecular crystallinity. Higher ethanol content increased the quantity of substance diffusing from plastic film. PBS and PBSA are more suitable for packaging hydrophilic foods than alcoholic beverages. PBS exhibited a lower migration rate than PBSA due to its more rigid polymer matrix. Remarkably, BO‐films exhibited 31% and 41% lower diffusion coefficients (D) compared with thin films, but significantly higher partition coefficients (KP,F) by 44% and 267% for BO‐PBS and BO‐PBSA, respectively. This suggests a stronger affinity of migrant for BO film matrix. However, at 70°C, PBSA films may be hydrolyzed with a high ethanol, resulting in an inadequate diffusion model. The diffusion–reaction concept should be implemented for a better fit. These findings provide valuable insights for selecting appropriate packaging materials and predicting migration under diverse conditions, ultimately promoting consumer safety.