Permeabilities and water vapor transmission rates for commercial polymer films

Abstract High molecular weight polymers have become well established as packaging or container materials. Unlike metallic and ceramic barriers, however, polymer films are known for their semipermeable nature; that is, they permit small gaseous and vapor molecules to migrate through their atomic/molecular structures. Since the intrusion of oxygen/water from the surrounding air or the loss of water/carbon dioxide from a packaged product can be detrimental to the shelf life of the product, the steady state transmission rate of a polymer film has become an important property characteristic of polymers to be used for packaging. An attempt has been made in this study to review the transmission data of commercially available polymer films. The three molecular species O 2 , CO 2 , and H 2 O were of particular interest. Since these permeability data vary over five orders of magnitude, several log‐log plots were constructed in order to assist decision making in film selections. Data for 34 different polymers are given. The effects of order or crystallinity, the presence of plasticizers, and the effects of laminated layering are discernible. It is the latter modification (laminating) that possesses demonstrable potential for improving the barrier properties of polymer films used for packaging purposes.