Copyrolysis Characteristics of Polyvinyl Chloride, Polyethylene and Polypropylene Based on ReaxFF Molecular Simulation

Reactive force field molecular dynamics (ReaxFF MD) simulation was used to study the copyrolysis behaviour of waste plastics i.e., polyvinyl chloride (PVC), polyethylene (PE), and polypropylene (PP) from three perspectives: (1) gas phase products, (2) reaction route, and (3) activation energy. The results demonstrate that the thermogravimetric (TG) experiment's findings and the weight loss characteristics of PVC/PE/PP copyrolysis obtained by ReaxFF MD simulation were consistent. Copyrolysis changed the amount of gas phase products generated, the direction of free radical movement, and the range of temperatures at which they were produced in considerable quantities. Due to the transfer of chloride (Cl) radicals, both PE and PP had a detrimental synergistic impact on the production of hydrogen chloride (HCl). Based on the first-order reaction kinetics model, the copyrolysis of waste plastics significantly lowered the total activation energy of the mixture, and the activation energy of PVC/PE/PP ternary blend system decreased most significantly.