Structural and electronic properties of polyethylene terephthalate (PET) from polarizable molecular dynamics simulations

The environmental and economic challenges posed by the widespread use and disposal of plastics, particularly polyethylene terephthalate (PET), require innovative solutions to mitigate their impact. Such mitigation begins with understanding physical properties of the polymer that could enable new recycling technologies. Although molecular simulations have provided valuable insights into PET interactions with various PET hydrolases, current additive force fields neglect the electronic polarization effects inherent to PET interactions. Here, we present parameters for PET polymer and its derivatives that are compatible with the Drude polarizable force field. Our parameter fitting protocol accurately reproduces electrostatic properties from quantum mechanical calculations. We then studied electronic properties of PET amorphous slabs and PET crystal films, revealing a crucial electronic polarization response of PET residues at the interface with water or vacuum, yielding insights into the modulation of electrostatic properties by solvent molecules. Finally, we showcase the interaction between a carbohydrate-binding protein and the PET crystal film, revealing the role of electronic polarization in enhancing binding affinity. This study represents the first extension of the Drude polarizable force field to a synthetic polymer, offering a robust tool for exploring PET material properties and advancing the design of efficient (bio)technologies for addressing plastic pollution.