Abstract

SYNTHESIS AND CHARACTERIZATION OF SUPER-ABSORBENT HYDROGELS BASED ON POLYACRYLAMIDE WITH SAGO AGRICULTURAL APPLICATIONS

Jeevitha Vedaiyan and Lynda Merlin*

Abstract

A kind of novel sago starch-based super absorbent polymer (SBSAP) with excellent water absorbency capacity (WAC) was synthesized by the graft polymerization of acrylamide (AAM), cross linker (N, N’- methylene-bisacrylamide, or N, N’-MBA, with sago starch. Sago starch (SG) based graft copolymers are becoming increasingly important due to its remarkable adhesion, high water absorbency and biodegradability. The various factors that influenced the water absorbency of the modified sago starch were studied, including AAM content, sago starch content, and weight ratio (to monomer)2% and 5%, cross-linker and initiator. The optimal conditions were found as follows: (N, N’-MBA) 1%: m (AM) 1g: m (sago starch) 2%, and also the swelling studies of PAAMS-2 and PAAMS-5 was 1784 %and 1616% respectively. The comparative study of hydrolytic stability of all the hydrogels shows 5% starch incorporated polyacrylamide hydrogels has better hydrolytic stability when compared to PAAM and PAAMS-2 hydrogels. The characteristics of the hydrogels were also investigated by Fourier Transform Infrared (FT-IR), scanning electron microscope (SEM), Thermo gravimetric analysis and Differential Scanning Calorimetric. The results indicated that the undulant surface and broad network structure offer the hydrogels excellent water absorbency. Therefore, the developed hydrogel may be widely applicable in agriculture and could provide a minimum wastage of water, utilization of fertilizer nutrients, as soil conditioners, water retainers, and bio-remediating agents.

Keywords: Water absorbency capacity; starch; superabsorbent polymer; gel strength.