Infrared linear dichroism as a tool to evaluate volatile guest partition between amorphous and nanoporous‐crystalline polymer phases

Desorption kinetics of ethene, propene, and butadiene from films exhibiting axially oriented nanoporous‐crystalline δ phases of syndiotactic polystyrene (s‐PS) have been followed by gravimetric and infrared linear dichroism measurements. The reported data can be rationalized by assuming that, after the initial desorption mainly involving molecules absorbed in the amorphous phase, most gaseous molecules are included as guest in the nanoporous‐crystalline phase. This allows establishing a simple method to evaluate guest partition between nanoporous‐crystalline and amorphous polymeric phases, which possibly can be applied for most volatile guest molecules. The described method also allows establishing the presence of one guest molecule (ethene, propene, or butadiene) per cavity of the nanoporous δ form. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012