Sorption of vapour mixtures of methanol and dimethyl carbonate in PDMS: Experimental study

• We propose a feasible method for the measurement of sorption of vapour mixtures in polymers.
• Sorption data for methanol–dimethyl carbonate vapour mixtures in PDMS are reported.
• Cooperative sorption was identified.
• An extended GAB model for mixtures of vapours was derived and successfully applied.

We report an original experimental method for the characterization of the sorption of binary vapour mixtures in polymers. Measurements of sorption of vapour mixtures can reliably identify and quantify the cooperative and competitive sorption, which can limitedly be predicted from the data on sorption of pure components, and on which scarce data are available. The method combined the sorption gravimetry and the analysis of sorbate using Fourier-transform infrared spectroscopy. The sorption of binary vapour mixtures of methanol and dimethyl carbonate in cross-linked poly (dimethylsiloxane), PDMS, was measured at 40 °C. A clear cooperative sorption effect of dimethyl carbonate on methanol was observed. To effectively parameterize the sorption of the vapour mixtures in the polymer, an extension of Guggenheim Anderson de Boer (GAB) model was derived. Overall, the proposed method represents a feasible way of measuring the sorption of mixtures of vapours in polymers.

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