[article]
Titre : |
Testing of starch-based carbohydrate polymer coatings for enhanced urea performance |
Type de document : |
texte imprimé |
Auteurs : |
M. Y. Naz, Auteur ; S. A. Sulaiman, Auteur |
Année de publication : |
2014 |
Article en page(s) : |
p. 747-756 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Catégories : |
Amidons BorateUn borate est un composé de bore et d'oxygène avec des éléments électropositifs.L'ion borate est BO2-.
Le bore trouvé dans la nature est toujours sous la forme d'un borate. Parfois, il est combiné à un silicate pour former un borosilicate.
L'ion borate se trouve sous diverses formes. En solution aqueuse, on trouve : l'acide borique, H3BO3 et en milieu alcalin, l'ion dihydrogénoborate, H2BO3-, l'ion hydrogénoborate, HBO32-, et enfin l'ion borate, BO2-. Le borate peut former divers ions polymères. Le plus commun est l'ion tétraborate, B4O72- ; on a également l'ion hydrogénotétraborate, HB4O7-. On trouve également du triborate, du pentaborate, etc. Les divers ions métaborate ont pour formule empirique : BO2-, et forment des composés métaborates.
Les borates peuvent former des structures anioniques compliquées et comprenant de très nombreux atomes, à l'image des silicates. Colles:Adhésifs Hydrates de carbone Morphologie (matériaux) Revêtements organiques Urée
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Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
In this study, starch–urea–borate adhesives were developed for coating the slow release urea. The physical properties of the developed adhesives were studied as a function of temperature, heating time, stirring rate, and pH. It was found that for certain specific adhesive composition, pH and stirring rate, the complete gelatinization time and corresponding adhesive viscosity do not remain constant with temperature. The suspension heated at 75°C reached its maximum viscosity after 21 min of heating, thereafter, remained constant over time. In contrast, the suspension heated at 80°C reached its peak viscosity after 12 min of heating. Further heating after 12 min caused a steady decrease in viscosity from its peak value of 450–339 cP. Once the adhesive physical properties were completely understood, a dripping solution technique was used to coat the urea granules with coating thickness ranging from 0.15 to 0.7 mm. It was noticed that the overall nutrients release time of the coated urea was three times higher than the uncoated urea. It was also concluded that the mechanical strength of coated urea strongly depends on the adhesive composition and coating thickness. |
Note de contenu : |
- MATERIALS AND METHODS : Development of starch adhesives - Characterization of starch adhesives - Fluidized bed coater
- RESULTS AND DISCUSSION : Optimization of adhesive parameters - Characterization of adhesive coatings - Coated urea efficiency |
DOI : |
10.1007/s11998-014-9590-y |
En ligne : |
https://link.springer.com/content/pdf/10.1007%2Fs11998-014-9590-y.pdf |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=22057 |
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 11, N° 5 (09/2014) . - p. 747-756
[article]
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