Facultad Regional San Francisco

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Author: search.filters.author.Nicolau, Verónica V.Subject: search.filters.subject.Atrazine

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    Superficies Sólidas a partir de Resinas Poliéster Insaturadas Modificadas con Aceite de Ricino Maleinizado: Biodegradación por el Ataque de Hongos Filamentosos
    (Universidad Tecnológica Nacional, 2017-03-30) Bernard, Mariana del Valle; Nicolau, Verónica V.; Estenoz, Diana
    Debido al impacto ambiental causado por el uso creciente de polímeros derivados del petróleo, existe un gran interés en el desarrollo de nuevos polímeros basados en fuentes renovables. Se busca diseñar materiales que exhiban buenas propiedades finales durante su uso y que presenten biodegradabilidad al final de su vida útil. En ese sentido, el aceite de ricino puede ser funcionalizado y empleado como sustituto parcial de resinas poliéster insaturadas en la producción superficies sólidas. El trabajo experimental involucro la síntesis y caracterización del aceite de ricino maleinizado, la degradación de los polímeros por hidrólisis química y enzimática de Aspergillus niger y Alternaria sp por un período de 230 días, y la caracterización de los polímeros (antes y después de la degradación) y de los compuestos de degradación por técnicas gravimétricas y GC-masa, respectivamente.
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    Microparticles based on ionic and organosolv lignins for the controlled release of atrazine
    (Journal of Hazaourdos Materials, 2018-07-02) Taverna, María E.; Busatto, Carlos Alberto; Lescano, Maia Raquel; Nicolau, Verónica V.; Zalazar, Cristina; Meira, Gregorio; Estenoz, Diana
    Lignins are natural polymers of the lignocellulosic biomass. Nowadays, there is a growing interest in developing value-added products based on lignins due to their renewability, low cost and abundance. In this work, lignin microspheres from organosolv and ionic isolation processes were prepared for the controlled release of atrazine. Microspheres were prepared by the solvent extraction/evaporation technique. The controlled release of atrazine from organosolv and ionic lignins microparticles was studied in water. Mobility experiments were performed in an agricultural soil from Argentina. The results showed that microparticles prepared using dichloromethane as the dispersed phase were spherical, while lignins dispersed in ethyl acetate produce irregular microparticles. Organosolv lignin microparticles presented higher encapsulation efficiency for all herbicide loads. About 98% and 95% of atrazine was released in 24 and 48h approximately from organosolv and ionic lignin microparticles, respectively. The release profiles of atrazine from both lignin microparticles were not affected by the herbicide load. Atrazine mobility experiments in soil showed that about 80% of free atrazine was leached in 37 days, while 65.0% and 59.7% of the herbicide was leached from ionic and organosolv lignin microparticles, respectively. Thus, atrazine-loaded microparticles could reduce leaching compared to a commercial formulation of free atrazine.