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Descripción
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| The availability of large quantities of IF-WS2 and INT-WS2 nanopowders has led to an extensive investigation of their properties suggesting numerous applications for friction and wear reduction, for electronics devices and for the reinforcement of polymers. Recently the mechanical behavior of IF/INT-WS2 was studied and their favorable influence on polymer properties was demonstrated. The tensile strength of multiwall inorganic nanotubes is around 15-20 GPa and the maximum strain (before breaking) exceeds 10% attesting to the unique combination of high strength and flexibility. Promising results have been obtained with respect to the mechanical, thermal, and tribological behavior of different polymers like polyphenylene sulfide (PPS), Nylon 6, epoxy, poly(etheretherketone) (PEEK), poly(methyl-methacrylate) (PMMA), isotactic polypropylene (iPP), etc., which were reinforced by adding tiny amounts (0.1-2 wt.%) of IF/INT nanoparticles [1-3]. Despite the extensive work performed on several polymers reinforced with IF/INT-WS2, little or nothing has been done in the very important area of biopolymer reinforcement. In this work we report the preparation and characterization of novel biodegradable polymer nanocomposites with tungsten disulfide inorganic nanotubes. The biopolymer matrix, poly(3-hydroxybutyrate) (PHB), is one of the most extensively researched and utilized biodegradable and renewable thermoplastic polyesters. Morphological and structural investigation of the new PHB/INT-WS2 systems confirms good dispersion of the INT-WS2 in the PHB matrix. It was shown that the INT-WS2 accelerate the crystallization of PHB, and an increment of 35 ºC in the crystallization temperature of PHB was observed for as little as 0.1 wt.% INT added. This corresponds to the highest value observed to date for PHB formulations using specific nucleating agents or nano-sized fillers. Further, these nanocomposites show an improvement in both tribological and mechanical (hardness and modulus) properties with respect to pure PHB evidenced by friction and nanoindentation tests. For example, by only 0.1 wt.% of INT-WS2 the Young's modulus of the nanocomposite increased by 17 %, and the hardness by up to 10%. The friction coefficient (?) measured after 1000 cycles for pure PHB was ? = 0.5 compared to ? = 0.2 for PHB impregnated with 1 wt.% of inorganic nanotubes, indicating a 60% improvement. Certainly a variety of industrial applications can be foreseen for such biocompatible systems. Acknowledgement: This work was supported by the Spanish Ministry of Economy and Competitivity (MINECO), Project MAT-2010-21070-C02-01. MN would also like to acknowledge the MINECO for a ?Ramón y Cajal? Senior Research Fellowship. 1. M. Naffakh, M. Rem?kar, C. Marco, M. A. Gómez and I. Jiménez, J. Mater. Chem, 2011, 21, 3574-3578. 2. C. S. Reddy, A. Zak, E. Zussman, J. Mater. Chem., 2011, 21, 16086-16093. 3. M. Naffakh, A. M. Díez-Pascual, C. Marco, G. Ellis and M. A. Gómez-Fatou, Prog. Polym. Sci. 2013, 38, 1163-1231. | |
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Internacional
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Si |
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Nombre congreso
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COINAPO (Composites Materials of Inorganic Nanotubes and Polymers) 2013 topical meeting on ?Nanoparticle-polymer composites? |
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Tipo de participación
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960 |
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Lugar del congreso
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Crete (Greece) |
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Revisores
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ISBN o ISSN
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DOI
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Fecha inicio congreso
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14/10/2013 |
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Fecha fin congreso
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16/10/2013 |
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