Permeability of carbon dioxide and nitrogen gases through SiO2 and MgO incorporated ENR/PVC membranes

Abstract

Two mixed-matrix membranes (MMM) for gas permeability test were prepared by introducing inorganic fillers (silica (SiO2) and magnesium oxide (MgO)) in the composite blend of epoxidized natural rubber (ENR) and polyvinyl chloride (PVC). Inclusion of SiO2 and MgO particles in the membranes resulted in pores formation as observed through scanning electron microscopy. Thermal study demonstrated that there were interaction between the fillers and polymer matrix with SiO2 exhibited better interaction. SiO2 was also observed to disperse more evenly in the membrane compared to MgO. The permeability of carbon dioxide (CO2) and nitrogen (N2) gases was measured in order to determine the effects of SiO2 and MgO in CO2/N2 separation performance of the ENR/PVC/filler membranes. CO2 was found to exhibit higher permeability compared to N2 for all the membranes. The gas permeability of ENR/PVC/SiO2 membrane was significantly higher than ENR/PVC/MgO and ENR/PVC membranes. Interestingly, despite having lower permeability, MgO-filled membrane exhibited higher CO2/N2 selectivity. When compared to the Robeson’s upper bound, it was found that introduction of fillers had improved gas separation performance of ENR/PVC membrane.