Papers by Keyword: Superabsorbent Composite

Abstract: A novel poly(2-acrylamido-2-methylpropa-nesulfonicacid-co-acrylamide) / attapulgite (P(AMPS-co-AM)/APT) high-salt superabsorbent composite was synthesized through graft polymerization in aqueous solution by microwave irradiation. The structure of the composite was characterized by infrared spectra (FTIR).The influence of the content of monomer, microwave power and the ratio of attapulgite clay on water absorbency was investigated. The swelling behaviors and the water retention of Superabsorbent resin with different APT content were also examined. The results show that the graft copolymerization took place between APT and organic monomers. Adding an appropriate amount of APT in resin can effectively improve the absorption capacity and salt-water performance. Microwave power is 390W, APT amount is 7.5% (mass fraction),The water absorbency of resin in distilled water and 0.9wt% NaCl were 1460g / g and 114 g / g. The resin has a faster absorption rate and strong water retention, the appropriate increase the amount of APT can significantly speed up the rate of the resin absorbent and improve its water retention.

Abstract: The polyacrylamide/starch-acrylic acid graft copolymer/bentonite composites with different concentrations of the bentonite and starch-acrylic acid graft copolymer were prepared by in-situ polymerization. The influence of the concentration of the bentonite and starch-acrylic acid graft copolymer on the water absorbency was investigated. The water absorbency of 115 g/g could be achieved with the composite composed of 50wt% bentonite, 17wt% starch-acrylic acid graft copolymer and 33wt% polyacrylamide. The excellent absorption and retention performance of the composite makes it potential to be applied in the model of Rain garden.

Abstract: The fly ash with a loose and porous structure has definite absorbent ability, which has a good effect on soil improvement. Illite belongs to clay minerals, it has absorbent ability and higher potassium, which can improve the soil fertility. In this study, poly(acrylic acid sodium-co-acrylamide)(PAANa-AM)/fly ash-illite superabsorbent composite was firstly prepared by solution polymerization. The structures were characterized using scanning electron microscope, X-ray diffraction, and infrared spectrum. The results showed that the fly ash and illite dispersed well in the composite. The K⁺ in illite was replaced by Na⁺ in acrylic acid sodium and thus the illite structure turned into paragonite during the process of preparing composite, however, the structure of fly ash was maintained in the composite. Moreover, the hydroxide radical in illite reacted with the carbonyl group in acrylic acid during polymerization. The best absorbent capacities of the composite in distilled water, tap water and normal saline were 1695, 445 and 106 g/g, respectively, which exceeded the requirements of The National 863 Program and Ministry of Agriculture of People’s Republic of China. The potassium release was measured using atomic absorption spectrometry and the results indicated that the composite can release 12.80% of the potassium ion in fly ash and illite. The superabsorbent material has low cost and favors improvement of soil and potassium-deficiency.

Abstract: A kaolin/sodium lignosulfonate graft acrylic acid and acrylamide superabsorbent composites(KLPAAM) prepared by solution polymerization are used for the equilibrium absorbency test of KLPAAM superabsorbent composite in different metal ion salt solutions. The effects of the solution concentrations on the equilibrium absorbencies in CuCl₂, ZnCl₂, FeCl₃ and AlCl₃ solutions are in order: CuCl₂<ZnCl₂<FeCl₃<AlCl₃. The solution concentrations and the pH values have an important effect on the equilibrium absorbencies. There are different pH values, 3.0 in FeCl₃ and ZnCl₂, 4.25 in AlCl₃ and 6.0 in CuCl₂ solution when the equilibrium absorbencies quickly increase with the pH values of the solutions. And then they reach their relative define values, in which the pH value is 3.8 in FeCl₃, 3.5 in ZnCl₂ and 5.5 in AlCl₃ solution. The absorbency obviously increases again when the pH value is larger than 7.0 in ZnCl₂ solution. They are slightly affected by the solution temperatures, that is, slightly decreases with increasing solution temperatures.