3 Hydroxyvalerate
Mostrando 1-12 de 54 artigos, teses e dissertações.
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1. Variation analysis of bacterial polyhydroxyalkanoates production using saturated and unsaturated hydrocarbons
ABSTRACT Polyhydroxyalkanoates (PHA) are efficient, renewable and environment friendly polymeric esters. These polymers are synthesized by a variety of microbes under stress conditions. This study was carried out to check the suitability of waste frying oil in comparison to other oils for economical bioplastic production. Six bacterial strains were isolated
Braz. J. Microbiol.. Publicado em: 2017-12
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2. The influence of natural clay and organoclay vermiculite on the formation process of bionanocomposites with poly (3-hydroxybutyrate-co-3-hydroxyvalerate)
ABSTRACT During the last decades, a lot of research work focused on several biodegradable and biosourced polyesters for the purpose of reducing the non-degradable polymer wastes. These polyesters are particularly considered to be promising polymers for biomedical applications and short life-time products like packaging. As these packagings are rapidly discar
Matéria (Rio J.). Publicado em: 02/10/2017
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3. PHBV/cellulose nanofibrils composites obtained by solution casting and electrospinning process
ABSTRACT In this work, nanobiocomposites of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) reinforced with cellulose nanofibrils (CNFs) were produced by electrospinning and solution casting process. CNFs were obtained by sulfuric acid hydrolysis from Imperata brasiliensis fibers. Nanocomposites loaded with 1 (wt. %) of CNFs were prepared using a mixtur
Matéria (Rio J.). Publicado em: 20/07/2017
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4. Thermo-Mechanical Properties of P(HB-HV) Nanocomposites Reinforced by Nanodiamonds
Several studies of biodegradable polymers and copolymers have been carried for different applications in the biomedical area. This current study aims to develop a biocomposite to be used as an orthopedic device, using poly(3-hydroxybutyrate-co-3-hydroxyvalerate) P(HB-HV), a biodegradable copolymer, with 94%HB and 6%HV, as matrix; and nanodiamonds (ND) with p
Mat. Res.. Publicado em: 26/06/2017
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5. Photodegradation and Photostabilization of Poly(3-Hydroxybutyrate)
The present work is concerned with the photodegradation and photostabilization of poly(3-hydroxybutyrate) (PHB) biopolymer. Two commercial grades of PHB were investigated, containing of 4.0% and 6.2% of hydroxyvalerate (HV) comonomer, named PHB1 and PHB2, respectively. Injection moulded specimens were exposed to ultraviolet radiation (UV-A) in the laboratory
Mat. Res.. Publicado em: 13/05/2016
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6. 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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7. Biodegradation of films of low density polyethylene (LDPE), poly(hydroxibutyrate-co-valerate) (PHBV), and LDPE/PHBV (70/30) blend with Paecilomyces variotii
The increased consumption of plastics in the world has been a subject of great concern and special attention by the scientific community. The aim is to promote development of materials that are biodegradable in a shorter time upon disposal in the environment. The most used synthetic plastics are difficult to biodegrade because they are made of long hydrocarb
Polímeros. Publicado em: 2015-02
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8. Volatile fatty acids influence on the structure of microbial communities producing PHAs
Polyhydroxyalkanoates (PHAs) can be produced by microorganisms and are a biodegradable alternative to fossil-fuel based plastics. Currently, the focus is on reducing production costs by exploring alternative substrates for PHAs production, and on producing copolymers which are less brittle than monomers. Accordingly, this study used a substrate consisting of
Braz. J. Microbiol.. Publicado em: 2014-06
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9. Influence of poly(ethylene grycol) - (PEG) on the properties of influence of poly(3-hydroxybutyrate-CO-3-hydroxyvalerate) - PHBV
Films of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) - PHBV with polyethylene glycol (PEG) were prepared by casting solvent evaporation. The thermal behavior, morphology, crystallinity and molecular weight of these films were studied by the following techniques: differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray diffraction (
Polímeros. Publicado em: 11/06/2013
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10. Poly(3-hydroxybutyrate-co-3- hydroxyvalerate) nanoparticles prepared by a miniemulsion/solvent evaporation technique: effect of phbv molar mass and concentration
Miniemulsification and emulsion/solvent evaporation techniques were combined to produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanoparticles. Those nanoparticles were prepared with different PHBV molar masses and PHBV concentrations to verify their effect on the final particle size. Nanoparticles with an average diameter of 133 nm were obtained
Braz. J. Chem. Eng.. Publicado em: 2013-06
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11. Properties of melt-processed poly(hydroxybutyrate-co-hydroxyvalerate)/starch 1: 1 blend nanocomposites
Melt blending of 1:1 poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and glycerol-plasticized starch (TPS) was performed in the presence of an organically-modified montmorillonite, incorporated at 2.5, 5, 7.5 and 10 wt% amounts. Scanning electron micrographs (SEM) revealed the role of the organoclay as a compatibilizing agent for the immiscible blend. Th
Polímeros. Publicado em: 28/05/2013
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12. Coprecipitation of safrole oxide with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in supercritical carbon dioxide
5-(Oxiran-2-ilmetil)-1,3-benzodioxol ou epóxi-safrol (SO) vem sendo estudado ao longo dos anos devido a suas propriedades dependentes da concentração, como indução à apoptose e transdiferenciação celular. A coprecipitação do SO com um polímero biodegradável e biocompatível, poli(3-hidroxibutirato-co-3-hidroxivalerato) (PHBV), foi realizada utili
J. Braz. Chem. Soc.. Publicado em: 2013-02