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Orientador(es)
Resumo(s)
When a pesticide is released into the environment, most of it is lost before it reaches its target. An effective
way to reduce environmental losses of pesticides is by using controlled release technology. Microencapsulation
becomes a promising technique for the production of controlled release agricultural
formulations. In this work, the microencapsulation of chlorophenoxy herbicide MCPA with native
b-cyclodextrin and its methyl and hydroxypropyl derivatives was investigated. The phase solubility study
showed that both native and b-CD derivatives increased the water solubility of the herbicide and inclusion
complexes are formed in a stoichiometric ratio of 1:1. The stability constants describing the extent of
formation of the complexes have been determined by phase solubility studies. 1H NMR experiments were
also accomplished for the prepared solid systems and the data gathered confirm the formation of the
inclusion complexes. 1H NMR data obtained for the MCPA/CDs complexes disclosed noticeable proton
shift displacements for OCH2 group and H6 aromatic proton of MCPA provided clear evidence of inclusion
complexation process, suggesting that the phenyl moiety of the herbicide was included in the hydrophobic
cavity of CDs. Free energy molecular mechanics calculations confirm all these findings.
The gathered results can be regarded as an essential step to the development of controlled release
agricultural formulations containing herbicide MCPA.
Descrição
Palavras-chave
Phenoxyacetic acid herbicides MCPA b-Cyclodextrin Inclusion complex
Contexto Educativo
Citação
Editora
Elsevier