Abstract

Effect Of Crosslinker On Swelling Pattern Of Crosslinked Poly(Acrylamide -Sodium Methacrylate) Superabsorbent Copolymers

Author(s): K.Mohana Raju, Y.Murali Mohan, P.S.Keshava Murthy, G.Nagarjuna

Crosslinked superabsorbent copolymers composed of acrylamide (AAm) and sodium methacrylate (SMA) were obtained by the free-radical copolymerization using ammonium persulfate (APS)/N,N,N,N-tetramethyl ethylenediamine (TMEDA) initiating system at room temperature in aqueous solution. Different compositions of sodium methacrylate with a fixed concentration of acrylamide and crosslinker were prepared and studied their equilibrium water content (EWC) and , swelling and diffusion kinetic parameters (i.e., initial swelling network constant, swelling rate constant, maximum swelling equilibrium, network structure constant and type of diffusion, etc). The superabsorbent copolymer formation was confirmed by IR spectroscopy. The effect of swelling medium temperature and the influence of salinity on swelling behaviour was investigated. The influence of various reaction parameters, such as, crosslinker, initiator, activator concentrations, and polymerization temperature on the swelling behaviour was investigated in detail. The network structure variation with the variation of crosslinker concentration was studied by SEM analysis. The pH effect and de-swelling behaviour was also studied for the copolymers. Because of higher swelling and water retention capacity of these materials we can find application in agricultural and horticultural applications.