Towards a Better Understanding of Delamination of Multilayer Flexible Packaging Films by Carboxylic Acids.

ABSTRACT: Recycling multilayer plastic packaging is challenging due to its intrinsic compositional heterogeneity. A promising route to increase recycling rates for these materials is delamination, which allows recycling the polymers separately. Yet, this process is not well understood on a fundamental level. This study aimed to obtain first principles-based insights of the delamination mechanism of multilayer flexible packaging film (MFPF) with carboxylic acids. Delamination of MFPFs was described through a model based on Fick's first law of diffusion and first-order dissolution kinetics of polyurethane adhesives. The model was experimentally tested on 5 different MFPFs at different temperatures (50-75 °C), formic acid concentrations (50-100 vol %), and solid/liquid (S/L) ratios (0.005, 0.025, and 0.12 g mL^-1 ). Under the studied conditions the model proved to successfully estimate the delamination time of MFPF with the average Theil's Inequality Coefficient (TIC) value of 0.14. Essential for scaling-up delamination processes is the possibility to use high S/L ratios as the solubility of the adhesive is rarely limiting.

SUBMITTER: Ugduler S 

PROVIDER: S-EPMC8518906 | biostudies-literature | 2021 Oct

REPOSITORIES: biostudies-literature