Poly 3 Hydroxybutyrate Phb
Mostrando 13-24 de 83 artigos, teses e dissertações.
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13. Environmental Stress Cracking of Poly(3-hydroxibutyrate) Under Contact with Sodium Hydroxide
Environmental stress cracking (ESC) is one of the most important causes of polymer premature failure, occurring when a combination of mechanical load and an aggressive fluid is applied. The phenomenon is well know by polymer producers and product designers but its mechanisms are not very well understood. Although the ESC effects of many commercial polymers a
Mat. Res.. Publicado em: 2015-04
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14. Glicólise do poli(3-hidroxibutirato) por via enzimática
Poly(3-hydroxybutyrate), PHB, is a polymer with broad potential applications because of its biodegradability and biocompatibility. However, its high crystallinity is a limiting factor for many applications. To overcome this drawback, one strategy currently employed involves the reduction of the molecular weight of PHB with the concomitant formation of end-fu
Quím. Nova. Publicado em: 2014-06
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15. The effect of additives interaction on the miscibility and crystal structure of two immiscible biodegradable polymers
Poly lactic acid (PLLA) is a promising biopolymer, obtained from polymerization of lactic acid that is derived from renewable resources through fermentation. The characteristic brittleness of PLLA is attributed to slow crystallization rates, which results in the formation of the large spherulites. Its glass temperature is relative high, above room temperatur
Polímeros. Publicado em: 2014
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16. Separación de fases y cristalinidad en mezclas epoxy/poli-3-hidroxibutirato
In this work, epoxy/poly-3-hydroxybutyrate (PHB) blends in two different proportions, 90/10 and 85/15, were studied. For this purpose, the samples were submitted to 80ºC and 120ºC for the curing process of epoxy. The phase separation and the crystallization were analyzed using optical microscopy and differential scanning calorimetry. Likewise, the lamellar
Polímeros. Publicado em: 28/05/2013
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17. Estudo da blenda poli(3-hidroxibutirato) / poli(etileno glicol). / Poly(3-hydroxybutyrate) / poly(ethylene oxide) blend study.
Esse projeto visa a melhoria das propriedades mecânicas e de processabilidade do Poli(3-hidroxibutirato) (PHB) para futuras aplicações. Foram preparados filmes de blendas de PHB por dissolução em clorofórmio. Poli(etileno glicol), com massa molar de 300 (PEG) ou 4.000.000 g mol-1 (PEO), foi misturado em proporções de 5 a 30 % em massa e análises ter
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/12/2011
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18. Efeito do tempo e do recozimento nas propriedades mecânicas e de biodegradação de materiais baseados em poli(3-hidroxibutirato) (PHB). / Effect of time and annealing on the mechanical properties and biodegradation of poly(3-hydroxybutyrate) (PHB) - based materials.
O polímero Poli(3-hidroxibutirato) - PHB - é sintetizado e consumido por microorganismos, o que o torna um material muito interessante e adequado aos problemas ambientais atuais. Porém, sua baixa tenacidade e estabilidade térmica são algumas das principais desvantagens em relação aos principais polímeros de engenharia. A mistura com polímeros modifi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 03/08/2011
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19. Production and characterization of poly-3-hydroxybutyrate from crude glycerol by Bacillus sphaericus NII 0838 and improving its thermal properties by blending with other polymers
The aim of this work was to study the production of poly-3-hydroxybutyrate (PHB) under nitrogen limited conditions by Bacillus sphaericus NII 0838 using crude glycerol from biodiesel industry as sole carbon source. Effect of various process parameters on PHB production such as glycerol concentration, inoculum size and pH of the medium were optimized. Charact
Brazilian Archives of Biology and Technology. Publicado em: 2011-08
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20. Miscibility influence in the thermal stability and kinetic parameters of poly (3-hydroxybutyrate)/poly (ethylene terephthalate) sulphonated blends
The thermal degradation of miscible and immiscible poly (3-hidroxy butyrate) PHB/ poly (ethylene terephthalate) sulphonated (PETs) blends was investigated using thermogravimetric analyses. Model-free kinetic analysis, Vyazovkin and Flynn-Wall-Ozawa's methods, were used to determine the apparent activation energy in the whole interval of degradation of the pu
Polímeros. Publicado em: 11/06/2010
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21. Compatibilization and degradation study of Polypropylene/Poly(3-hydroxybutyrate) (PP/PHB) blends. / Estudo da compatibilização e da degradação de blendas polipropileno/poli (3-hidroxibutirato) (PP/PHB).
In this work Polypropylene/Poly(3-hydroxybutyrate) (PP/PHB) blend was studied. In particular the compatibilization and the influence of a previous photodegradation on the biodegradation of the blend were investigated. In order to understand the photodegradation of the blends it was also necessary to study the photodegradation of PHB. The compositions of the
Publicado em: 2010
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22. Production of biodegradable plastics using sugarcane bagasse hemicellulosic hydrolysate. / Produção de plásticos biodegradáveis utilizando hidrolisado hemicelulósico de bagaço de cana-de-açúcar.
The aim of this thesis is to produce poly3-hydroxybutyrate (P3HB) and poli-3-hidroxibutirate-co-3-hydroxyvalerate (PHB-co-3HV), biodegradable polymers, using hemicellulosic hydrolysate, rich in xylose, from sugarcane bagasse. Metabolic flux analysis in silico of xylose metabolism indicated that, though metabolism redirection is possible to increase P3HB yiel
Publicado em: 2010
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23. Comportamento de celulas osteoblasticas sobre biomateriais polimericos / Osteoblast cells behavior on polymeric biomaterial
Os polímeros biorreabsorvíveis, tais como, PHB, PCL e PLGA, têm sido estudados como dispositivo para engenharia de tecidos por serem biocompatíveis, suportarem o crescimento e diferenciação celular e os produtos de sua degradação serem atóxicos. No entanto, a escolha do biomaterial depende das necessidades exigidas para uma determinada aplicação.
Publicado em: 2010
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24. Blends of poly(3-hydroxybutyrate) and random copolymers : phase behavior and crystallization kinetics / Blendas com poli(3-hidroxibutirato) (PHB) e copolimeros aleatorios : comportamento de fases e cinetica de cristalização
Blendas do polímero biodegradável poli(hidroxibutirato) foram preparadas com os seguintes copolímeros aleatórios: poli(estireno-co-acrilonitrila)-SAN; poli(estireno-co-metacrilato de 2-hidróxietila)-S-Hema; poli(metacrilato de metila-co-vinil fenol-P(MMA-co-VPh). Os copolímeros SAN foram sintetizados via copolimerização em massa, enquanto os copolím
Publicado em: 2009