Preparation and characterization of ABS/HIPS heterogeneous cation exchange membranes with various blend ratios of polymer binder

Abstract

In this research, acrylonitrile–butadiene–styrene (ABS)/high impact polystyrene (HIPS) blend heterogeneous cation exchange membranes were prepared by solution casting technique using tetrahydrofuran as solvent and cation exchange resin powder as functional group agent. The effect of blend ratio of polymers binder (ABS to HIPS) on properties of the prepared membranes was studied. Ultrasonic was used to appropriately disperse particles in the matrix of membrane. Scanning optical microscopy showed that sonication had a significant effect on the high distribution of resin particles in membranes. Moreover images showed a relatively uniform surface for membranes. The increment of HIPS ratio in casting solution led to a decline in water content of membranes. Ion exchange capacity, ion permeability, ionic flux, electrical conductivity and current efficiency of membranes were initially decreased by the increment of HIPS ratio to 10 wt% and then increased with increment from 10 to 80 wt%. However, they were decreased again in HIPS membrane. Opposite trend was found for energy consumption of membranes. Membrane potential, permselectivity, transport number and surface charge density of membranes were improved by improving the HIPS ratio to 80 wt%. In addition, the oxidative stability of membranes was increased and their mechanical strength was decreased by lowering the ABS ratio. Membrane with 20:80 (w/w) blend ratio of polymer binder (ABS to HIPS) exhibited appropriate efficiency and electrochemical properties in comparison with other prepared membranes in this research. However its mechanical strength was lower than the others. Moreover swelling of the prepared membranes was negligible.