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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

A detailed understanding of the thermal degradation processes taking place during the melt processing of bio-nanocomposites is crucial in order to increase the processing window of these materials. In this work, the influence of the content of neat clay and modified-clay on the thermal degradation of a biodegradable bacterial poly(3-hydroxybutyrate) (PHB) matrix, was studied. The modified clay consisted in a multi-treated organobentonite, which was first acid-activated, then silylated and further modified by cationic exchange treatment. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) tests were carried out to investigate the thermal behavior of the different nanocomposites as a function of temperature, whereas size exclusion chromatography (SEC) runs were performed to analyze the changes on the molecular weight distribution of the PHB. The obtained results reveal that the organic modifiers of the muti-treated clay promote the thermal degradation process leading to a dramatic decrease in the molecular weight of PHB. It was demonstrated that the degradation mechanism of PHB was not modified by the incorporation of neat clay or modified-clay, and that the process can be well described by the Avrami–Erofeev random nucleation model (m = 4), in which the reaction is controlled by initial random nucleation followed by overlapping growth.

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

This chapter is an overview of the effect of the different nanofillers on the crystallization performance of polymer matrices. The most relevant nanocomposites were classified according to the nature of the reinforcement.In general, it was reported that the way of processing greatly affected the crystal sizes, crystalline structure, and the degree of crystallinity of semicrystalline polymer nanocomposites, modifying the performance of the material. Therefore the influence of the different crystallization processes on barrier, thermal stability, and dynamic or mechanical properties of nanocomposites is described. Moreover, it was observed that the crystallization mechanism of polymers in the nanocomposites strongly depends on the intrinsic characteristics of the nanoparticles and the matrix, and in consequence the dispersion of the filler in the matrix.This chapter focuses on the studies about the effect of different types of nanofillers on several aspects of polymer crystallization, such as kinetics, crystal structure, nucleation effect, as well as spherulitic growth and morphology. 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 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

The effect of different contents of nano-fillers: carbon black (CB), bentonites (original (Bent) and modified with phosphonium salt (B-TBHP)) and commercial modified montmorillonite (C30B) on the thermal degradation of phenolic resin was studied by thermogravimetric analysis (TG). The obtained results strongly suggest that CB was the most effective filler in improving the thermal stability of the resol type phenolic matrix. The previous results were associated with the thermal stability of each filler but also with the compatibility between the matrix and the filler and the effect of filler incorporation on the crosslinking degree of the neat matrix. The profile of the apparent activation energy with the conversion of the thermal degradation process for the resol and the nanocomposites was obtained using three isoconversional methods: Friedman, KAS and Vyazovkin. The curves were correlated with the degradation steps of the phenolic resin observed by TG, showing a similar degradation mechanism for all the systems. By means of the method of invariant kinetic parameters (IKP), it was possible to estimate the preexponential factor and the activation energy to describe the degradation process of the resol and the nanocomposites in the thermal fragmentation zone, between 350 and 600 ºC. It was determined that the Sestak?Berggren model was the one that best describes the thermal degradation experimental data. Then, a comparison between the experimentally obtained and the simulated differential degradation curves shows that the resulting model was certainly accurate to predict the thermal degradation process of the resol and the nanocomposites. Fil: Asaro, Lucía. 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: Alvarez, Vera Alejandra. 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: Rodriguez, Exequiel Santos. 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

Isothermal and non-isothermal crystallization kinetics of nanocomposites of poly(3-hydroxybutyrate) (PHB) with 4 wt% of montmorillonite Cloisite®Na+ (CNa+) and chemically modified clays Cloisite®15A and 93A (C15A and C93A) prepared by solution casting have been investigated by differential scanning calorimetry. Nanoparticles addition did not significantly affect the crystallinity and melting temperatures of the PHB, regardless the type of clay. Several models such as the Liu-Mo, Avrami, Lauritzen–Hoffman and isoconversional were found to provide a fairly satisfactory description of the crystallization kinetics of PHB and its nanocomposites. The results showed a slight effect of the CNa+ and C93A on the crystallization kinetics parameters of PHB. However, a retarded effect on the crystallization rate of the polymer was found when C15A clay was added. It was attributed to the high dispersion of this clay in the polymer. Consequently, the dispersion and type of clay influence the crystallization kinetics of PHB.

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

Poly(3-hydroxybutyrate) (PHB) films and its nanocomposites were obtained by casting. Three types of modified clays were used in order to improve the compatibility with the PHB. The films were characterized determining the thermal properties and the non-isothermal crystallization kinetic parameters from the melt. No change in the melting temperature of PHB was observed with the clay addition but the Tg diminished for the nanocomposites with the clay modified by ion exchange (MI) and by acid activation (MAI) to the PHB, due to the effect of the organic modifiers. From non-isothermal studies, it was observed a diminution of the peak of the crystallization temperature of PHB with the addition of clay at all of the cooling rates studied. The nanocomposites with MI and MAI exhibited the slowest crystallization rate among the materials, studied by the Liu–Mo model. However, the addition of the clay modified by silylation (MAGI) did not affect the crystallization rate of PHB. Effective activation energy (Ea) of the crystallization process of PHB and the nanocomposites was calculated by the isoconversional methods of Friedman and Vyazovkin. The Ea of the PHB increased with the addition of any type of the clays studied, but the rate of crystallization was reduced. 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: 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: 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

The aim of this study is to analyze different strategies of modification of bentonite (Bent) combining reactions of cationic exchange, silylation and acid activation. Six samples of modified bentonite were prepared: silylated bentonite (S-Bent), acid-activated bentonite (A-Bent), exchanged clay (E-Bent), silylated and acid-activated clay (S-A-Bent), exchanged and acid-activated clay (E-A-Bent), and exchanged, silylated and acid-activated bentonite (E-S-A-Bent). To study the effectiveness of the different treatments, X-rays diffraction analysis, thermogravimetric analysis, Fourier transform infrared spectroscopy and water absorption tests were performed. After silylation reaction, the modified clay presented an increase in the basal spacing as well as a significant reduction in the equilibrium water uptake percentage. The results were markedly improved when the silylated and acid-activated bentonite was further modified by cationic exchange reaction. 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: Ollier Primiano, Romina 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: Alvarez, Vera 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: Schroeder, Walter Fabian. 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

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.