Synthesis of poly(acrylic acid)/sodium humate superabsorbent composite for agricultural use

Abstract

A novel poly (acrylic acid)/sodium humate superabsorbent composite was synthesized by graft copolymerization reaction of acrylic acid (AA) on sodium humate micropowder using N,N 0 -methylenebisacrylamide (MBA) as a crosslinker and potassium peroxydisulfate (KPS) as an initiator in aqueous solution. The effects on water absorbency of factors such as reaction temperature, initial monomer concentration, and degree of neutralization of AA, amount of crosslinker, initiator, and sodium humate were investigated. The superabsorbent composite was characterized by scanning electron microscopy, and the graft copolymerization reaction of AA on sodium humate micropowder was characterized by IR spectroscopy. Results obtained from this study show that the water absorbency of the superabsorbent composite synthesized under optimal conditions for synthesis with a sodium humate content of 5.3% exhibited absorption of 684 g H 2 O/g sample in distilled water. Waterretention in soil is enhanced by the use of the superabsorbent composite. The effect of superabsorbent composite on the growth of corn is reported. The superabsorbent composite may be of use as water management materials for agriculture purposes in desert and drought-prone areas.

Superabsorbent polymers: A review on the characteristics and applications of synthetic, polysaccharide-based, semi-synthetic and ‘smart’ derivatives

“…drug release [39,41], and wound healing [39,42,43]), while hydrogels are more often used for applications in which swelling is less preferred such as in tissue engineering [39,44] or (disposable) contact lenses [45,46]. SAPs are also strongly used in the agricultural sector as soil conditioners, nutrient carriers and water reservoirs (to conserve water in dry areas) [4,[47][48][49][50][51][52][53][54]. Other applications include water purification and water-blocking tape.…”

Crack Mitigation in Concrete: Superabsorbent Polymers as Key to Success?

“…It can also have its purpose in the field of water purification [ 43 ] and as a water-blocking tape [ 35 , 44 ]. Another field of interest is the agricultural sector, for e.g., soil conditioners, nutrient carriers and water reservoirs applied to conserve water in dry areas [ 35 , 45 , 46 , 47 , 48 , 49 ]. A final application which gains more and more attention lately is the use of SAPs in mortar and concrete [ 50 ], and especially for self-sealing and self-healing of cracks [ 30 , 31 , 32 , 51 , 52 , 53 , 54 , 55 , 56 ].…”

Advances in chitosan-based superabsorbent hydrogels

“…Sabadini et al 105 superabsorbent composites can enhance the water retention in soil, which may be used in desert and drought areas. 4 Jamnongkan et al prepared fertilizer controlled release hydrogel which exhibited the equilibrium swelling ratio in the range 70-300% and increased the water retention ability of the soil. 77…”

“…Thus, they can respond to the stimuli of the surrounding environment. Therefore, these good properties have drawn signicant attention for applications in personal hygiene, 3 agriculture, 4,5 construction and building, 6,7 water purication, 8 drug delivery and controlled release, [9][10][11] and biomedical applications. 12 Currently, most of the commercially available and disposable superabsorbent products such as baby diapers are made from petroleum-based vinyl monomers, and thus they are poor in degradability and environmental friendliness.…”