Preparation and Characterization of Nanoclay Polymer Composites (NCPCs) Loaded with Urea

In the present paper, three slow release clay-polymer nanocomposite fertilizers were synthesized, (1) acrylic acid + acrylamide (AA +Am NCPC) (2) acrylic acid + wheat flour starch (WF NCPC) and (3) acrylic acid + sodium alginate (Na-Alg NCPC) via free radical polymerization in the presence of bentonite. The nanocomposites were characterized by XRD, FTIR, SEM and SEM-EDX. Results revealed that NCPCs were participated in the graft polymerization reaction with AA and the bentonite layers were exfoliated and basically dispersed in the composites on a nanoscale after the polymerization. The three (AA +Am, WF and Na-Alg) polymer nanocomposite synthesized under optimum reaction conditions exhibits the maximum swelling ratio of 68.5, 54.3, and 81.9 g/g in distilled water respectively. The nitrogen analysis of WF, AA+AM and Na-Alg NCPC was 19.10, 24.13% and 26.07%, respectively. The N release percentage at 30^th day in soil reached around 87.22, 59.91, 63.77 and 60% of total applied N for Urea, AA+AM, WF and Na-Alg NCPC, respectively. In this way NCPCs showed the double function that delays nitrogen release and stores water in it.