Slow Release of Urea as a Source of Nitrogen from Some Acrylamide and Acrylic Acid Hydrogels

Helaly, F. M.; Essawy, Hisham; El‐Nashar, D. E.; Maziad, Nabila A.

doi:10.1081/pte-200048712

Cited by 25 publications

(8 citation statements)

References 12 publications

(6 reference statements)

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“…Calculation of the diffusion coefficient D from the release rate K is possible: The value calculated for the diffusion coefficient D of urea in SSRNF hydrogel is about (2.4 ± 0.2)× 10 −6 cm 2 s −1 , which is in general agreement with the diffusion coefficients of urea in hydrogel, i.e. about 10 −5 –10 −6 cm 2 s −1 , as reported in the literature 31, 32…”

Section: Resultssupporting

confidence: 85%

Preparation of superabsorbent slow release nitrogen fertilizer by inverse suspension polymerization

Liu

Liang

Zhan

et al. 2006

Polymer International

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A superabsorbent, slow release nitrogen fertilizer (SSRNF) was prepared by inverse suspension polymerization of partially neutralized acrylic acid using N,N′‐methylene bisacrylamide as a crosslinker and ammonium persulfate as an initiator in the presence of urea. The polymer was characterized using infrared spectral analysis, and network structural parameters such as molecular weight between crosslinks (Mc) and crosslink density (q) were calculated. The effects of reaction conditions, such as reaction time, reaction temperature, initiator, crosslinker and the degree of neutralization of acrylic acid, on water absorbency were investigated. The nitrogen content of SSRNF synthesized under optimal conditions was 22.7%, and the water absorbencies were about 965 g g−1 in distilled water and 185 g g−1 in tap water. The nitrogen slow release behaviors of the SSRNF in water and water retention capacity of soil with the SSRNF were also investigated. A possible slow release mechanism was proposed and the release rate constant K and the diffusion coefficient D of urea in the hydrogel was calculated. The results showed that the product not only had good slow release properties but also excellent soil moisture preservation capacity, which could effectively improve the utilization of fertilizer and water resources simultaneously. Therefore, the SSRNF is a multifunctional water managing material, which would find application in agriculture and horticulture, especially in drought‐prone areas where the availability of water is limited. Copyright © 2006 Society of Chemical Industry

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Section: Resultssupporting

confidence: 85%

Preparation of superabsorbent slow release nitrogen fertilizer by inverse suspension polymerization

Liu

Liang

Zhan

et al. 2006

Polymer International

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“…In some polymer‐clay or polymer‐silica nanocomposites, it was reported that the strength of the hydrogel can be increased by incorporating a small amount of inorganic species . In comparison, similar amphoteric hydrogel structures without reinforcing inorganic components were usually very fragile especially on swelling . However, on further incorporation, strain generally decreased with the increase of strength.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of amphoteric nanocomposite hydrogels with ultrahigh tensibility

Liu

et al. 2014

Polymer Composites

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Amphoteric nanocomposite hydrogels (NC gels) were synthesized by in situ copolymerization of acrylic acid (AA) and N [-3(dimethylamino)propyl] methacrylamide (DMAPMA) in an aqueous dispersion of laponite XLG. Mechanical analyses demonstrated that this type of hydrogels had a combination of high tensile strength and excellent stretchability. The tensile strength was increased by 5 times up to 316 kPa when the laponite content was increased from 0.1 wt% to 20 wt%, and a maximum fracture strain of 2,317% was achieved for hydrogels containing 3 wt% laponite. Additionally, the marked improvements in strength were achieved with minimal sacrifice of the tensibility. This work provided a continuation to previous efforts of the preparation and properties of ionic NC gels. POLYM. COMPOS., 36:538-544, 2015.

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“…Microwave-mediated biochar-hydrogel composites [52] Polyvinylpyrrolidone (PVP)/carboxylmethyl cellulose [53] Acrylamide and acrylic acid based hydrogels [54] Glutaraldehyde crosslinked chitosan-poly(vinylalcohol) hydogel [55] Borassus aethiopum starch and Maesopsis eminii hydrogels [56] Poly(acrylonitril)-based poly acrylic acid hydrogels, [57] Acrylamide and N-hydroxymethyl acrylamide hydrogel [58] Natural rubber, cassava starch crosslinked by glutaraldehyde hydrogel [59] Starch phosphate carbamate hydrogel [60] Starch cross-linked acrylic acid and acrylamide hydrogel [61] Poly (acrylamide-co-acrylic acid)/kaolin gel [62] Poly(maleic anhydride-co-acrylic acid) hydrogel [63] Poly(acrylic acid)/attapulgite/sodium humate composite hydrogel [64] Poly(acrylamide) and methylcellulose based hydrogels [65] N,N 1 -MBA crosslinked acrylic acid [12] Table 5.…”

Section: Typical Hydrogel Referencementioning

confidence: 99%

Smart Polymer Hydrogels as Matrices for the Controlled Release Applications in Agriculture Sector

Venkatachalam¹,

Pushparaju²

2023

Hydrogels - From Tradition to Innovative Platforms With Multiple Applications

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Synthetic polymer hydrogels and modified natural polymer hydrogels are widely and increasingly used in agriculture, health care textiles, effluent treatment, drug delivery, tissue engineering, civil concrete structure, etc. Among them, the use of hydrogels in agricultural and horticultural sectors as matrices for the controlled release of water, various primary and secondary nutrients has drawn significant attraction from researchers, scientists, and industry persons due to their smartness with reference to controlled release characteristics based on plant requirement. Since the use of these hydrogels for controlled release application ensures the minimum utilization of water and plant nutrients in fields. Besides, this will bring down the overloading of fertilizer, soil contamination, and water pollution such as eutrophication, nitrate pollution, and micronutrient imbalance. This chapter is focused on the class of hydrogels that are used for the controlled release application in the agricultural and horticultural sectors as matrices, the possible methods of fine-tuning their structures for improving their fertilizer uptake and release behavior, safety aspects, and environmental issues.

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Slow Release of Urea as a Source of Nitrogen from Some Acrylamide and Acrylic Acid Hydrogels

Cited by 25 publications

References 12 publications

Preparation of superabsorbent slow release nitrogen fertilizer by inverse suspension polymerization

Preparation of superabsorbent slow release nitrogen fertilizer by inverse suspension polymerization

Synthesis of amphoteric nanocomposite hydrogels with ultrahigh tensibility

Smart Polymer Hydrogels as Matrices for the Controlled Release Applications in Agriculture Sector

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