Biodegradation Studies of Starch Based Composite Superabsorbents

The potential of a new starch based composite consisting of acrylamide, a crosslinking agent, N,N'methylene-bis-acrylamide and sand (white quartz) to act as a superabsorbent polymer was investigated. The modification of starch by grafting with acrylamide induced hydrophilic behaviour in the matrix, which increased its water absorbing capacity remarkably and also enhanced its biodegradability by sludge water and microorganisms (Bacillus cereus and Eischerichia coli). The amount of carbon dioxide released during biodegradation was studied and the process of biodegradation through soil burial was also investigated. The composite was characterized by IR, TGA and XRD techniques. The XRD data reveals the composites to be more crystalline than starch and homopolymer. The surface morphology was examined by SEM, and was found to show distinct differences after biodegradation. The composite may be used as a water retainer for agricultural and horticultural purposes in desert and drought-prone areas.