Melting and crystallization of poly(3-hydroxybutyrate): effect of heating/cooling rates on phase transformation

Wellen, Renate Maria Ramos; Rabello, Marcelo S.; Júnior, Inaldo Cesar Araujo; Fechine, Guilhermino J. M.; Canedo, Eduardo L.

doi:10.1590/0104-1428.1961

Cited by 42 publications

(27 citation statements)

References 30 publications

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“…Some studies have indicated this multiple melting behavior of PHB is contributted to different crystalline structure in PHB during DSC melting scan [47][48][49] . Hong et al 49 refer to the smaller peak as a melting temperature of small and imperfect crystallites that formed during evaporation of the solvent.…”

Section: Dsc Of the Fibers And Polymeric Matrixmentioning

confidence: 99%

Polyhydroxybutyrate Composites with Random Mats of Sisal and Coconut Fibers

et al. 2016

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Biodegradable polymeric composites using natural fibers have been investigated aiming to mitigate environmental impacts. In this paper, polyhydroxybutyrate (PHB) composites obtained using random mats of sisal and coconut fibers by compression molding in a hydraulic press, and the fiber content varied between 10% and 15% relative to the weight of the polymer. Thermal analyses were performed such as Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Flexural and tensile tests were performed before and after conditioning in climate chamber with temperature and moisture. The results of thermal analysis show that the thermal stability of the materials remained, both PHB without fiber as for composites with natural fibers mats. The results of mechanical tests indicated that the PHB without fibers and composites showed similar flexural strength values, while the results of the tensile test PHB without fibers showed resistance to higher tensile composite.

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Section: Dsc Of the Fibers And Polymeric Matrixmentioning

confidence: 99%

Polyhydroxybutyrate Composites with Random Mats of Sisal and Coconut Fibers

et al. 2016

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“…Thus, studies of processing conditions and the crystallization process are necessary for understanding and controlling the properties of the final product. Researches are being conducted with the objective to optimize those conditions [6][7][8][9][10]; there are previous works with neat PHB, PHB/PS blends, PHB/carbon black and PHB/babassu composites, the improvement of PHB properties, the increase in thermal stability upon addition of carbon black, decrease in crystallinity degree with PS addition, rational crystallization control through applying defined heating/cooling DSC rates were reached in our works [6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 91%

“…The disadvantages related to its oversized spherulites, such as brittleness and mechanical performance loss, can be avoided by the introduction of fillers and inorganic additives, which improve toughness and electrical and magnetic properties [12]. Investigations were realized about the usage of PHB in many compounds, such as PHB/talc, PHB/polyethylene terephthalate (PET), PHB/polyamide 11 (PA 11), PHB/carbon black, and it was observed a faster crystallization from the molten [13].…”

Section: Introductionmentioning

confidence: 99%

Comparative study of the effect of TiO2 and ZnO on the crystallization of PHB

et al. 2017

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RESUMOForam preparados compósitos PHB/TiO 2 e PHB/ZnO num misturador interno de laboratório, a cristalização foi investigada por calorimetria exploratória diferencial (DSC), com taxas de aquecimento e resfriamento entre 5 e 30 °C/min e a superfície de fratura de seletas composições analisada por microscopia eletrônica de varredura (MEV). Através das imagens de MEV foi observado que as nanopartículas de ZnO e TiO 2 estão bem dispersas na matriz de PHB. Por DSC, observou-se que a adição de TiO 2 e ZnO modificou a temperatura e taxa de cristalização do PHB, sem afetar significativamente a cristalinidade total. Em geral, a adição da carga TiO 2 promoveu alterações mais significativas na matriz de PHB, comportando-se como um agente nucleante. Palavras-chave: PHB, cristalização, TiO 2 , ZnO, DSC. ABSTRACTPHB/TiO 2 and PHB/ZnO compounds were prepared in a laboratory internal mixer. Crystallization was investigated by differential scanning calorimetry (DSC) with heating and cooling rates ranging from 5 to 30 ºC/min. Fractured surface of selected samples was analysed by scanning electron microscopy (SEM). From the SEM images, it was observed that ZnO and TiO 2 nanoparticles were properly dispersed in the PHB matrix. DSC studies revealed that the addition of TiO 2 and ZnO changed the temperature and crystallization rate but did not affect the total crystallinity significantly. In general, TiO 2 behaved as nucleating agent greatly influencing the PHB crystallization.

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“…The study of crystallization and melting behavior is basic to understand and control of material properties and processing necessary to get them. An experiment was developed in order to understand the effect of the thermal cycles in the polymer phase transition suggesting that the crystallinity of PHB can be controlled by the thermal cycles of heating and cooling to which the material is subjected [82].…”

Section: Aging and Mechanical Characteristicsmentioning

confidence: 99%

From Obtaining to Degradation of PHB:Material Properties. Part I

et al. 2017

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This paper presents a review of the chemical, physical and morphological characteristics, as well as the existing applications and mechanisms for the production of poly (3-hydroxybutyrate). This biopolymer, which is obtained from renewable sources, degrades when exposed in biologically active environments and is biocompatible, that is, it is not rejected by the human body in health applications. However, in spite of presenting similar properties with some conventional plastics, the PHB exhibits fragile behavior and thermal instability when processed. The literature proposes the use of blends, the development of copolymers or the insertion of additives in an attempt to improve the mechanical and thermal properties of PHB. Key words: Biopolymers; polyhydroxyalkanoates (PHA); Polyhydroxybutyrate (PHB). Universidad EAFIT 269|From Obtaining to Degradation of PHB: Material Properties. Part I De la obtención a la degradación de PHB: Propiedades del material. Parte I ResumenEste artículo presenta una revisión de las características químicas, físicas y morfológicas, así como las aplicaciones y mecanismos existentes para la producción de poli(3-hidroxibutirato). Este biopolímero, que se obtiene a partir de fuentes renovables, se degrada cuando se expone en ambientes biológicamente activos y es biocompatible, es decir, no es rechazado por el cuerpo humano en aplicaciones de salud. Sin embargo, a pesar de presentar propiedades similares con algunos plásticos convencionales, el PHB exhibe comportamiento frágil e inestabilidad térmica cuando se procesa. La literatura propone el uso de mezclas, el desarrollo de copolímeros o la inserción de aditivos en un intento por mejorar las propiedades mecánicas y térmicas del PHB.Palabras clave: Biopolímeros; degradación de PHB; polihidroxialcanoato (PHA); polihidroxibutirato (PHB).

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Melting and crystallization of poly(3-hydroxybutyrate): effect of heating/cooling rates on phase transformation

Cited by 42 publications

References 30 publications

Polyhydroxybutyrate Composites with Random Mats of Sisal and Coconut Fibers

Polyhydroxybutyrate Composites with Random Mats of Sisal and Coconut Fibers

Comparative study of the effect of TiO2 and ZnO on the crystallization of PHB

From Obtaining to Degradation of PHB:Material Properties. Part I

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