Fabrication and characterization of gum ghatti-polymethacrylic acid based electrically conductive hydrogels

Abstract

Gum ghatti-polymethacrylic acid-polyaniline based electrically conductive hydrogel with an interpenetrated network (IPN) structure was prepared through a two step aqueous polymerization. In the first step, cross linked network of polymethacrylic acid onto Gum ghatti was prepared using N,N′-methylene- bis-acrylamide (MBA) and ammonium persulfate (APS) as a cross linker-initiator system under microwave irradiation. Optimum reaction conditions affording maximum percentage swelling were: solvent (ml) = 10, MAA (mol L-1) = 0.236 × 10-3, APS (mol L-1) = 0.175 × 10 -1, MBA (mol L-1) = 0.32 × 10-1, reaction time (s) = 85, microwave power (%) = 100 and pH 7.0. The semi-interpenetrating networks was converted into a IPN through the impregnation of poly(aniline) chains and resulting IPN was doped with HCl. The maximum conductivity (2.69 × 10-4 S cm-1) was observed with 2.0 N HCl and 0.658 × 10-3 mol L-1 of aniline. Synthesized IPN was characterized using different techniques like FTIR, SEM and XRD. The candidate polymer was also subjected for evaluation of its thermal behavior using TGA. © 2013 Elsevier B.V.