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Bio-based poly(lactic acid)/poly(3-hydroxybutyrate) (PLA/PHB) films were melt-blended with a natural hydrophobic plasticizer (glyceryl tributyrate, TB) at three different concentrations (10, 15 and 20% by weight per 100 parts of the blends) to study the effect of TB on the final properties of the materials. The pursued aim was to obtain a material with potential use in the packaging industry. Two different PLA/PHB ratios were used, 70/30 and 60/40, respectively. A full characterization of the developed blends was carried out, including the morphological, thermal, mechanical and barrier properties. The thermal test revealed the immiscibility between PLA and PHB by showing two glass transition temperatures for the blends and biphasic melt. Mechanical tests showed the increased in the elongation at break as the plasticizer content in films increased. The incorporation of PHB crystals in the PLA matrix displayed an improvement in the water barrier properties of materials. Finally, formulations PLA/PHB-TB with 15 wt% of plasticizer presented the best combination of properties suitable for the intended use in films manufacturing, showing toughness and ductility, good water barrier properties and transparency with slightly amber color. Fil: Iglesias Montes, Magdalena Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: D'amico, David Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Manfredi, Liliana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Cyras, Viviana Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina

The aim of this work was to study the preparation of bilayer films formed by soy protein isolate (SPI) and polyhydroxybutyrate (PHB). This was done using the lowest possible concentration of PHB to improve the functionality of SPI films as food packaging or for agricultural uses, specially reducing their water vapor permeability. The combination of both SPI and PHB seems to be a good alternative to prepare a completely biodegradable material taking advantages of the best properties of each component.

The effect of processing conditions (casting and extrusion) and plasticization on the disintegrability in compost of organically modified clay poly(3-hydroxybutyrate) nanocomposites was studied. Tributylhexadecylphosphonium bromide was used as organic modifier. As revealed by WAXS and TEM observations, Intercalated nano-biocomposites with clay stacks and some individually dispersed platelets were obtained. The melting temperature of the neat PHB diminished with the addition of plasticizer broadening the processing window.Biodegradation test revealed that while the clay slows down the degradation rate, the plasticizer increases the degradation of the samples, reaching a similar final percentage of disintegrability when both plasticizer and clay were added in the formulation. Fil: Puglia, D.. Universita Di Perugia; Italia Fil: Fortunati, E.. Universita Di Perugia; Italia Fil: D'amico, David Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina Fil: Miri, Valérie. Centre National de la Recherche Scientifique; Francia Fil: Stoclet, Grégory. Centre National de la Recherche Scientifique; Francia Fil: Manfredi, Liliana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina Fil: Cyras, Viviana Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina Fil: Kenny, J.. Universita Di Perugia; Italia

Polyhydroxybutyrate (PHB) has a significant instability at temperature close to the melting point. The aim of this work was to improve the thermal resistance of PHB by the addition of small amounts of two different types of clays: Cloisite® Na+ (CNa+) and Cloisite® 15A (C15A). C15A has more hydrophobic character and interlayer distance than CNa+. It was observed that the addition of the organically modified montmorillonite (MMT) increased by more than 15°C the thermal resistance of the PHB while the addition of CNa+ reduced it. This result was related to the different morphology of the final materials. The maximum in the degradation temperature of the nanocomposites with 4% of clay was in accordance with the maximum in the percentage of crystallinity. However, the interlayer gallery distance of the C15A was higher than the CNa+ in the PHB matrix, according to the better thermal stability of the C15A due to the higher barrier effect and the lower chain mobility. A slight increase in the Young modulus of the polymer was observed with the addition of C15A, due to the compatibility between the MMT and PHB. The calorimetric and microscopy results showed that clays did not accelerate the formation of PHB spherulites nucleus, but the lamellar velocity was accelerated. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Biodegradable polymeric blends based on poly(3-hydroxybutyrate) (PHB) and polylactic acid (PLA) were prepared by melt mixing. Trybutyrin, a bio-based plasticizer, was added at a fixed proportion in all blends. Crystal structure, percent crystallinity, miscibility, mechanical properties and permeation of fully biodegradable PHB/PLA blends were investigated in detail by Differential Scanning Calorimetry (DSC), Fourier Transformed Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), tensile tests and water vapor permeation tests. From the thermal test, two glass transition temperatures were found for the whole range of compositions, which reveals the immiscibility between PHB and PLA. Moreover, the biphasic melt further confirms this fact. Tensile tests showed an increase in the elongation at break with the PLA content. SEM images reveal debonding between the interfacial surfaces, which justifies the increase in the elongation at break. Water vapor permeation values for blends were slightly higher than that of the plasticized pristine polymer. The plasticized polymer blends showed valuable properties to extend the applications of PHB and PLA. Fil: D'amico, David Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Iglesias Montes, Magdalena Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Manfredi, Liliana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Cyras, Viviana Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina

Superparamagnetic nanocomposites were obtained by dispersion of oleic acidcoated magnetic ultrafine iron oxide nanoparticles (NPs) in poly(hydroxybutyrate) (PHB), a semicrystalline, biodegradable and biocompatible polymer. Film nanocomposites displayed an optically homogeneous structure formed by sub-micrometric clusters created by a strong NPs segregation that occurred during solvent evaporation and polymer crystallization. Number and size of clusters increased with the concentration of NPs producing a controlled shift in the blocking temperature but hardly affecting PHB crystallinity and melting temperature. The presence of NPs decreased the elastic modulus of PHB and slightly reduced its hardness, leading to materials with improved resistance to permanent damage. This softening effect was attributed to the oleic acid shell covering the iron oxide core of the NPs. The present results shed some light on the mechanisms controlling morphology of semicrystalline-based nanocomposites modified with ultrafine NPs, opening interesting possibilities for the design of materials with controlled functional properties. Fil: D'amico, David Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina Fil: Fasce, Laura Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina Fil: Hoppe, Cristina Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina Fil: López Quintela, M. Arturo. Universidad de Santiago de Compostela. Facultad de Quimica; España Fil: Cyras, Viviana Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina

Polymer nanocomposites, based on a bacterial biodegradable thermoplastic polyester, poly(hydroxybutyrate) (PHB), and unmodified montmorillonite Cloisite Na+ (CNa) and chemically modified Cloisite 15A and 93A (C15A and C93A), were prepared through a solution route. The nanostructure has been established through X-ray diffraction (XRD), while the nanocomposites were characterized by differential scanning calorimetry (DSC), contact angle measurements, and thermogravimetric (TGA) analysis. Disintegrability in composting conditions has been tested at certain times (0, 7, 14, 21, 28 and 35 days at 58 C) and the effect of different nanoclays on the properties of biodegraded films was deeply investigated. XRD results suggest a better dispersion for C15A and C93A based nanocomposites that present also a more surface hydrophobic nature respect to PHB matrix and PHB nanocomposite loaded with unmodified Cloisite. This result is in accord with disintegrability behavior of PHB nanocomposites. Visual observation, chemical, thermal and morphological investigations proved that the disintegration in composting conditions was faster for PHB-4CNa respect to the systems loaded with modified clays suggesting the possibility to modulate the disintegrability capacity of PHB selecting a specific filler. © 2013 Elsevier Ltd. All rights reserved.