Eco-Friendly Superabsorbent Synthesis Based on Polysaccharides

Superabsorbent polymers (SAPs) are a kind of materials which are widely used in many fields where the absorption of various aqueous solutions is prime importance. Given the fact that a great number of SAPs available on the global market are made from the poorly degradable and expensive materials, recently, there has been increasing interest in looking for low-cost and environmental friendly solutions in SAP production industry. In this study, three types of hybrid SAPs composites were synthesized through the graft polymerization of acrylic acid (AA) into three kinds of natural polysaccharides backbone chain, separately, which are: Hydroxyethyl cellulose (HEC), Xyloglucan (XG), and Guar gum (GG) in an aqueous solution, with ammonium persulfate (APS) as the initiator, N,N'-methylenebisacrylamide (MBA) as the cross-linker, and diatomite clay as an inorganic nano-filler. The FTIR and SEM characterization results suggested that three kinds of hybrid SAP composites were successfully synthesized with high porosity on the surface. The study about the capacity of water absorbent revealed that the optimized swelling ratios of the three superabsorbent composites (HEC-g-PAA/diatomite, XG-g-PAA/diatomite, and GG-g-PAA/diatomite) are 1174.85 g.g(-1), 1057.06 g.g(-1), and 692.83 g.g(-1), respectively. In addition, the effect of each parameter such as polysaccharide species and the content of polysaccharide, initiator, cross-linker, diatomite and the degree of neutralization toward the water absorbency capacity of the obtained SAP were determined and discussed.