Membrane from Technical Grade Poly(Vinyl Chloride): Preparation and Characterization

Sophisticated separation without membrane technology is unthinkable in modern chemical industries using process water and discharging effluents contaminated with various solid and liquid pollutants, but Bangladesh is far behind the advanced world in terms of membrane manufacturing and uses. This work initiates research in the field and successfully develops membranes from technical grade poly(vinyl chloride) (PVC) applicable in water and wastewater treatment. Porous structure observed by Scanning Electron Microscope looks somewhat finger like channel structure bounded from both upper and lower surfaces by thin skin layers, called ‘selective layer’. This resembles partially to ultrafiltration membrane structure. However, the pore-size distribution measured by Liquid displacement porometry, shows that the pore-sizes are in the typical microfiltration ranges. The membrane permeability decreases with an increase in the casting solution concentration. It is confirmed that micro- and ultra- filtration membranes can be prepared from PVC with desired pore-size distribution and ‘selective layer’ by phase inversion method varying the preparation parameters. This is a pioneering work in the country in developing polymer membrane preparation technique and would inspire young researchers to develop it further for applications in native industries.