Plasticized Starch/ Tunicin Whiskers Nanocomposites : 1. Structural Analysis

International audienceNanocomposite materials were obtained using glycerol plasticized starch as the matrix and a colloidal suspension of cellulose whiskers as the reinforcing phase. The cellulose whiskers, prepared from tunicin, consisted of slender parallelepiped rods with a high aspect ratio. After mixing the raw materials and gelatinization of starch, the resulting suspension was cast and evaporated under vacuum. The composites were conditioned at various moisture contents in order to evaluate the effect of this parameter on the composite structure. Th

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Version juin 2008.Projet réalisé dans le cadre du Programme de recherche et d'expérimentation du réseau de l'enseignement collégial privé

Dwarf cavendish as a source of natural fibers in poly(propylene)-based composites

Composite materials were prepared by com pounding and hot-pressing PP or MAPP and lignocellulosic fibers extracted from the rachis of Musa acuminate Colla var. Dwarf Cavendish banana tree. The fibers were used as raw filler or after a chemical treatment expected to remove most of the extractible compounds. The resulting materials were characterized using SEM, DSC, DMA, tensile tests and water sorption experiments. All results show that the main aspect involved in the interfacial adhesion between the polar filler and the non-polar matrix is the extraction of lignin and fatty substances. This results in higher values of the degree of crystallinity and crystallization temperature of the matrix, higher mechanical properties and lower water sensitivity. Scanning electron micrograph showing the cross section of the lignocellulosic filler obtained from rachis of banana tree: (a) raw, and (b) extracted fibers.info:eu-repo/semantics/publishedVersio

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A simple method for the melt extrusion of cellulose nano-crystal reinforced hydrophobic polymer

International audienceThe rheological properties of a dispersion of cellulose nanocrystals (CNCs) in an aqueous solution of polyoxyethylene (PEO) have been investigated. A peculiar behavior is reported. Upon adding CNC, the viscosity of the suspension first decreases and then increases. Adsorption of PEO chains on the surface of the nanoparticles has been suspected. Freeze-drying of this PEO-adsorbed CNC dispersion was performed, and the ensuing lyophilizate was extruded with low density polyethylene. Compared to neat CNC-based nanocomposites, both improved dispersibility and thermal stability were observed. This simple and physical method constitutes an approach of choice for the melt processing of CNC-based nanocomposites with a hydrophobic polymeric matrix applicable at the industrial scale

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Projet réalisé dans le cadre du Programme de recherche et d'expérimentation du réseau de l'enseignement collégial privé

Isolation and characterization of cellulose nanofibers from argentine tacuara cane (Guadua angustifolia kunth)

New trends in the area of material improvement are the use of natural nano-charges from renewable biomass, improving the value and sustainability of our country’s natural products. Bamboo is widely used in many countries of the world, although in Argentina, despite being commercialized and exported for the manufacture of wood floors, it goes unnoticed despite having native species. Therefore, researchers identified the native and exotic species present in our country and are working on novel uses. In this context, it is proposed the Argentine Tacuara Cane (Guadua Angustifolia Kunth), endemic plant as a new source of nanocellulosic materials, where stem fibers have been isolated using a green method achieving with yield of 45.9% of cellulose. The cellulose nanofibrils (CNF) were obtained using a green homogenization method. The CNF exhibited web-like long fibrous structure with the diameter of 10-20 nm. The crystallinity was 65.5%, as for the onset temperature of thermal decomposition was 212°C. The nanocellulose isolated from the Tacuara Cane seed fibers has a high potential to be used as a new source of cellulose-based nanofiller for the reinforcement of bionanocomposite films.Fil: Rodriguez Ramirez, Carlos Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Rol, Fleur. Université Grenoble Alpes; FranciaFil: Bras, Julien. Université Grenoble Alpes; FranciaFil: Dufresne, Alain. Université Grenoble Alpes; FranciaFil: Garcia, Nancy Lis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: D'accorso, Norma Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentina. Universidad de Buenos Aires; Argentin