Barrier properties of polyethylene terephthalate, atactic polypropylene, and cis-1,4-polybutadiene via molecular dynamics simulation

Parallel molecular dynamics simulations have been carried out to determine the permeability of O₂, N₂,and CO₂ through polyethylene terephthalate, polypropylene and cis-1,4-polybutadiene. 3-dimensional (bulk) and 2-dimensional (film) periodic samples of the polymer were utilised, with the 2D film being used in two different approaches designed to probe either solubility or permeability directly. Solubility was also estimated via a particle insertion technique. The molecular descriptions for both polymer and gas and the analysis method were verified against experimental data. Analysis of the simulation results was via inter-comparison between different gases, polymers, and simulation methods. In addition, the benefits and potential shortcomings of the different simulation techniques are discussed.