On the CO2 sorption and swelling of elastomers by supercritical CO2 as studied by in situ high pressure FTIR microscopy

- Simultaneous CO2 sorption and swelling of elastomers using high pressure FTIR microscopy.
- Investigation of seven elastomers for T = 50 to 110 °C from P = 5 to 15 MPa.
- All the elastomers displays a significant level of CO2 sorption about 20% at P = 15 MPa.
- The resulting swelling is linearly correlated to the CO2 sorption.
- Weak dependence of swelling and CO2 sorption upon temperature variation.

An FTIR (Fourier Transform InfraRed) microscope combined to a high pressure cell has been used to determine the CO2 uptake in several common elastomers. Both the CO2 sorption and the resulting swelling of the elastomers have been determined as function of pressure (P = 5-15 MPa) at constant temperature (T = 50 °C). A significant quantity of CO2 is sorbed in all studied elastomers, between 15 and 20% at T = 50 °C and P = 15 MPa for most elastomers and up to 30% for Ethylene Vinylacetate (EVM) in the same conditions. The resulting percentage of swelling of the majority of studied elastomers is significant (up to 30%), and varies quite proportionally with the CO2 mass uptake (linear variation with a slope equal to 1). The effect of temperature has been studied for Ethylene Propylene Diene (EPDM), between T = 50 °C and T = 110 °C (P = 5-15 MPa) and demonstrate that the swelling and CO2 sorption display only a weak variation in this temperature range.

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