Majaron, Vinicius F.
da Silva, Marisa G.
Polito, Wagner L.
Total Authors: 6
 Univ Estadual Paulista Julio de Mesquita Filho UN, Inst Quim, Ave Prof Francisco Degni 55, BR-14800900 Araraquara, SP - Brazil
 Embrapa Instrumentacao, Lab Nacl Nanotecnol Agronegocio LNNA, Rua 15 Novembro 1452, BR-13561206 Sao Carlos, SP - Brazil
 Univ Fed Sao Carlos, Dept Quim, Rodovia Washington Luiz, Km 235, BR-13565905 Sao Carlos, SP - Brazil
 Univ Sao Paulo, Inst Quim Sao Carlos, Campus Sao Carlos, BR-13566590 Sao Carlos, SP - Brazil
Total Affiliations: 4
APPLIED CLAY SCIENCE;
DEC 1 2020.
Web of Science Citations:
We proposed a nanocomposite system based on castor oil-derived polyurethane (PU) for controlling the release of fertilizers by an ion-exchange mechanism. PU coatings modified with less than 5% montmorillonite, a cation exchange material, successfully retarded the nitrogen release from urea granules, with less than 50% of the nutrient released within 18 days of immersion, as confirmed by soil incubation experiments. The same profile was observed for the phosphate release from monoammonium phosphate (MAP) granules coated with PU modified with hydrotalcite (less than 5% by weight), an anion-exchange material. The release times were proportional to the contents of the cationor anion-exchange materials, which exhibited specific correlations with the kind of nutrient released (i.e., cationic or anionic), confirming the diffusion barrier promoted by the PU coating structures. Our results demonstrated that the use of PU nanocomposites can significantly reduce the coating thickness with improved nitrogen and phosphorus release control, opening a new field for the investigation of controlled release fertilizers. (AU)