Polymer sorbents for phosphorus esters: II. Hydrogen bond driven sorption in fluoro‐carbinol substituted polystyrene

Abstract

AbstractA series of copolymers containing styrene and a fluorocarbinol substituted styrene, vinyl benzyl hexafluorodimethyl carbinol, were prepared by substitution of hexafluoroacetone on polystyrene followed by hydrolysis, and by copolymerization of styrene and substituted styrene monomers. Sorption of dimethyl methyl phosphonate, DMMP, vapor in the copolymers was examined at 135°C by the piezoelectric sorption method and at 135 to 165°C by Inverse Gas Chromatography, IGC, and the results were analyzed by the Flory‐Huggins equation. Both methods yield similar negative values of the Flory‐Huggins Chi parameter at 135°C, and the Chi values are observed to become increasingly negative to −4.9 as the percent substitution of the aromatic rings In the copolymer is increased to 54 mole percent. A simplified thermodynamic analysis, based on experimental studies of the hydrogen bond formed between DMMP and hexafluoro‐isopropanol, an analog of the fluoro‐carbinol, through infrared spectroscopy and calorimetry at ambient conditions, is shown to predict the Chi dependency on copolymer composition observed at 135°C to within the accuracy of the experimental observations, however, the analysis predicts a decrease in Chi with increasing temperature that is too high relative to values observed by IGC at temperatures greater than 135°C.