Examination of gas transport through polysiloxane open cell foams: effects of compression upon model flow, permeation parameters, and cell morphology

A study to test a model for gas flow through a polymer foam system was conducted. The goal was to quantitatively relate polymer foam compression and gas pressure drop across the specimen, to the gas flow through the foam. Foam cell morphology was studied to assess adequacy of the model to accommodate material characteristics. X-ray tomographic images were collected for polydimethylsiloxane (PDMS) foam material under various levels of compression. The intent was to implement a systematic analysis method of correlating some aspect of these images to the cell morphology in order to enhance understanding of the material characteristics. It was shown that x-ray tomography is a useful nondestructive method for understanding the compressive behavior of a mechanically loaded polymer foam. As a general trend, the experimentally obtained x-ray attenuation coefficient could be correlated with the effective density of the polymer foam, approaching values for the polymer resin as foam compression increased. Mechanical properties of the cellular polymer could also be elucidated.