Green synthesis of Moringa oleifera gum-based bifunctional polyurethane foam braced with ash for rapid and efficient dye removal

Abstract Natural gums, mainly composed of polysaccharides, are green feedstock to synthesize a variety of functional materials. Herein we report Moringa oleifera gum (MOG) to synthesize new bio-based polyurethane foam (MOG-PUF), wherein MOG acts as polyol for reaction with 4,4′−diphenylmethanediisocyanate via urethane linkages. MOG-PUF was used for the adsorption of malachite green (MG) dye from its aqueous solution and also tested for antibacterial activity. Synthesis of MOG-PUF and malachite green-loaded MOG-PUF (MG-loaded MOG-PUF) were successfully characterized using various analytical techniques. Batch experiment studies revealed almost 100% removal of MG using MOG-PUF within 30 min. Dye adsorption followed pseudo-second order kinetics and conformed Langmuir isotherm with maximum adsorption capacity ( q m ) of 125.945 mg/g. Moreover, MOG-PUF showed noticeable reusability having adsorption efficiency of ∼61% after 15th repeat cycle. Results of antibacterial study showed prominent zones of inhibition against four strains of bacteria, S. aureus , Enterococcus , P. aeruginosa and E. coli , thus revealing its strong antibacterial nature.