Sorption of organic liquids in poly(ethylene chlorotrifluoroethylene) Halar®901: Experimental and theoretical analysis

Sorption of liquids in polymers is an important factor for any application where polymers come into contact with an organic solvent. We report on sorption properties of hydrophobic poly(ethylene chlorotrifluoroethylene) Halar®901 in view of its potential application as a membrane material. For the first time, the liquid phase sorption of 34 common organic liquids such as linear C6-C10 alkanes, methyl-, ethyl- and propyl-derivates of benzene and cyclohexane and of linear-, branched- and cyclic- ethers, ketones, acetates and chloroderivates in the 1:1 alternating copolymer of ethylene and chlorotrifluoroethylene (ECTFE) is presented. The effects of solvent molecular structure and its physico-chemical properties on the total mass uptake are discussed in detail. Furthermore, two sorption-predictive methods developed from determined data allows to anticipate the behavior of solvents in Halar®901 based exclusively on three type of structural units (C-bone, functional groups, molecular geometry) or four (molar mass, surface tension, boiling temperature and Van der Waals volume) parameters only. A successful verification of our methods proved their versatility in predicting organic liquid sorption in ECTFE material Halar®901.