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

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 (MOGPUF), 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 (qm) of 125.945 mg/g. Moreover, MOG-PUF showed noticeable reusability having adsorption efficiency of similar to 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.