Gas permeability of deformed polyethylene films

✍ Scribed by H. Yasuda; A. Peterlin

• Publisher: John Wiley and Sons
• Year: 1974
• Tongue: English
• Weight: 887 KB
• Volume: 18
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1974.070180218

✦ Synopsis

Low-density polyethylene films strained up to 35% exhibit an initial increase of diffusivity and permeability which soon reach a maximum and subsequently drop to steadily decreasing values below those of the unstrained starting material. The sorption steadily increases and seems to approach a plateau. The maximum and the subsequent decrease are probably caused by significant, recoverable plastic deformation which seems to depress the tortuosity factor but not the free volume, as one concludes from the opposite trend of diffusion and sorption. Permanently deformed drawn or rolled films on the strain range from 0.5 through 3.0 exhibit a continuous decrease of diffusivity and permeability with an almost constant reduction of sorption. This postulates a decrease in free volume and a steadily decreasing tortuosity factor as a consequence of the gradually increasing fraction of the new, practically impermeable fibrous structure.