An investigation on surface resistivity of polypropylene fabrics modified with ionic liquids

In this study, polypropylene fabric was modified with two types of ionic liquids such as 1- ethyl-2,3-dimethylimidazolium ethyl sulfate (EIL) (2, 6, 10 %w/v in ethanol) and methyl-trin-butylammonium methyl sulfate (10, 15, 20 %w/v in ethanol)at different concentrations. Before modification, the fabrics were pretreated with chromic acid to activate the surface. The effect of the modifications was investigated by thermogravimetric analysis, surface resistivity measurements and scanning electron microscopy. The pre- treatment changed surface resistivity from 1010 to 1013 ohm/sq. The modifications with the ionic liquids decreased surface resistivity of the PP fabrics short and long-term periods in the range of 106 - 108 ohm/sq. Increasing the concentration of the ionic liquids can be considered as an efficient way to reduce the surface resistivity of PP. Thermal stability of the PP altered after modification. It was observed that a coating layer formed on surface of the fabric and in the gaps of the yarns of PP with modification. This environmentally- friendly method can be used as an alternative way for improving conductivity of PP fabrics generally characterized by their high surface resistivity.