Electrokinetic properties of acrylic acid‐ and methacrylic acid‐grafted polypropylene during chemically initiated graft copolymerization

Abstract

AbstractElectrokinetic properties such as zeta potential (ζ), surface charge density (σ) and surface conductivity (Ks) of polypropylene fibers and those grafted with acrylic acid and methacrylic acid have been studied using the streaming potential method. At pH 7, the zeta potential of −58.5 mV for control fibers reduced with increase in the amount of acrylic acid (16.2%) and methacrylic acid (28.2%) grafts to −38.15 mV and −38.30 mV, respectively. The drop in the negative zeta potential value is attributed to rendering polypropylene hydrophilic. The acrylic acid graft was found to be more effective than the equivalent amount of methacrylic acid graft in this respect due to the different chemical characters of the two graft copolymers. The negative zeta potential was also reduced to a considerable extent when cationic dye solution was streamed through the grafted polypropylene fibers, which is attributed to the deposition of dye cations on the negatively charged surface of the grafted fibers. The results on surface charge density and surface conductivity also indicated the hydrophilic character of grafted polypropylene.