Browsing by Subject "ACETILACION"
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artículo de publicación periódica.listelement.badge Development of poly(lactic acid) nanocomposites reinforced with hydrophobized bacterial cellulose(2020-01) Ávila Ramírez, Jhon Alejandro; Bovi, Jimena; Bernal, Celina; Foresti, María Laura; Errea, María Inés"Poly(lactic acid)/bacterial cellulose nanocomposites were prepared by solvent casting. Aiming to reduce the incompatibility between polar bacterial cellulose (BC) and the nonpolar poly(lactic acid) (PLA) matrix which induces filler aggregation and poor reinforcement dispersion, BC was acetylated by the use of a non-conventional route catalyzed by citric acid. The derivatized BC (AcBC) was incorporated into de PLA matrix at varying filler loadings, and optical, morphological, structural, thermal, tensile and barrier (water vapor) properties of PLA/AcBC in comparison with PLA/BC were evaluated. Noticeable changes in the nanocomposite properties were ascribed to the success of the route proposed to surface hydrophobize BC, which significantly improved its dispersibility within the PLA matrix and the matrix-filler interaction. By the way, the variation of filler loading allowed attaining remarkable increases in the nanocomposite films stiffness without significant reductions in tensile strength and water vapor permeability."artículo de publicación periódica.listelement.badge Nanocomposites based on poly(lactic acid) and bacterial cellulose acetylated by an α-hydroxyacid catalyzed route(2019-01) Ávila Ramírez, Jhon Alejandro; Cerrutti, Patricia; Bernal, Celina; Errea, María Inés; Foresti, María Laura"Poly(lactic acid) (PLA) nanocomposite films reinforced with acetylated bacterial cellulose nanoribbons were prepared by solvent casting. Acetylation of bacterial cellulose (BC) was performed by an innovative and sustainable direct solventfree route catalyzed by citric acid. The effect of derivatization and its extent on the morphological, optical, thermal and mechani-cal properties of the nanocomposites was analyzed. Data collected from the above studies showed that acetylation of BC nanoribbons clearly improved the nanofibers dispersion in the PLA matrix with respect to unmodified BC, which in turn resulted in increased transparency and mechanical properties of the nanocomposites produced."tesis de doctorado.listelement.badge Obtención y esterificación sostenible de nanocelulosa bacteriana para usos que requieren regular la polaridad de las nanofibras(2019) Ávila Ramírez, Jhon Alejandro; Foresti, María Laura; Errea, María Inés"El trabajo realizado en el marco de la presente Tesis se centró en evaluar la utilidad de una metodología novedosa de acetilación para la hidrofobización de nanofibras de celulosa bacteriana (BNC). En el curso del estudio, la ruta se extendió a otras formas de nanocelulosa, como son las membranas enteras de BNC y los nanocristales de celulosa de origen vegetal (CNC). La aplicación concreta pensada para las nanocelulosas modificadas fue su utilización como refuerzo de una matriz polimérica biodegradable hidrofóbica de interés comercial como es el ácido poliláctico (PLA). El objetivo final del trabajo fue obtener materiales compuestos biodegradables con propiedades mejoradas que dependen en gran medida de la eficacia con que se haya logrado la compatibilización entre refuerzo y matriz."