Permeability of carbon dioxide and nitrogen gases through SiO 2 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.