Polybutadiene
Mostrando 13-24 de 38 artigos, teses e dissertações.
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13. Síntese de poliuretanos modificados por óleo de mamona empregados em materiais energéticos
The aim of this work was to synthesize a polyurethane polymer matrix using castor oil as a polymer chain modifier, whose characteristics can be adjusted for use as a binder in the manufacture of energetic materials such as propellant and pyrotechnics for aerospace use. We attempted the partial substitution of hydroxyl-terminated polybutadiene (HTPB), a pre-p
Quím. Nova. Publicado em: 2013
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14. Ammonium Perchlorate and Ammonium Perchlorate-Hydroxyl Terminated Polybutadiene Simulated Combustion
Abstract: The combustion simulation of ammonium perchlorate was carried out with the software Chemkin, in two steps: the burning behavior of pure ammonium perchlorate and the one of formulated ammonium perchlorate with hydroxyl terminated polybutadiene binder. In both cases, the room pressure varied in order to verify its influence in the system. The burning
J. Aerosp. Technol. Manag.. Publicado em: 2012-03
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15. Nanocompósitos ternários de amido termoplástico e poli(Butadieno maleatado)
Liquid polybutadiene (PBLH) was modified with maleic anhydride (MA). The material (PBLHM) was characterized and used to prepare hybrid materials by blending with glycerol-plasticized cassava starch (TPS) and an organophilic clay at 5 wt% content. Processing was performed by extrusion under mild conditions and led to TPS/PBLHM/clay hybrids, at 95/5 to 85/15 T
Química Nova. Publicado em: 2012
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16. Synthesis and characterization of butadiene-1,3 and octene-1 copolymer prepared by a Ziegler-Natta catalyst based on neodymium
The aim of this work is to evaluate the influence of octene-1 incorporation in the polybutadiene chain on the polymerization reaction and polymer characteristics. Thus, copolymerization of butadiene-1,3 with octene-1 using a Ziegler-Natta ternary catalyst based on neodymium was performed. The weight ratios of butadiene-1,3/α-olefin 100/0, 99/1, 97/3, 95/5,
Polímeros. Publicado em: 01/11/2011
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17. Thermal aging of HTPB/IPDI-based polyurethane as a function of NCO/OH ratio
Thermal aging of hydroxy-terminated polybutadiene/isophorone diisocyanate (HTPB/IPDI)-based polyurethane was studied as a function of NCO/OH ratio (1.0 and 0.85). Samples were aged in air ovens at 50, 60, 65, and 70 ºC for periods of time from 1 to 34 weeks. Changes in chemical (swelling testing and FT-IR spectroscopy) and mechanical (tension testing and ha
Materials Research. Publicado em: 16/09/2011
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18. Diffusion of plasticizer in a solid propellant based on hydroxyl-terminated polybutadiene
The aim of this work was to determine the dioctyl azelate (DOZ) plasticizer diffusion coefficient (D) for samples containing the interfaces of rubber, liner and solid composite propellant based on hydroxyl-terminated polybutadiene (HTPB). The samples used in the diffusion study were aged up to 31 days after the cure period at 80 °C. A computer program imple
Polímeros. Publicado em: 12/11/2010
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19. The role of antioxidant on propellant binder reactivity during thermal aging
Abstract: Thermal aging of hydroxy-terminated polybutadiene (HTPB) stabilized with 2,6-di(tert-butyl)hydroxytoluene (BHT) was carried out at 60ºC from 1 to 11 weeks. Samples of 200 mL were stored in sealed 500-mL Erlenmeyer flasks under atmospheric pressure or vacuum and periodically withdrawn for physical and chemical analysis, infrared spectroscopy charac
J. Aerosp. Technol. Manag.. Publicado em: 2010-08
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20. Evaluation of the influence of the polymer-filler interaction on compounds based on epoxidized elastomeric matrix and precipitated silica
The introduction of epoxy groups into the main chain of elastomers has emerged as a promising alternative, considering the monitoring of polymer-filler interaction leading to changes in the properties of vulcanizates. The epoxidation reaction (in situ) was chosen to modify elastomers, such as polybutadiene (BR) and copolymer of styrenebutadiene- rubber (SBR)
Publicado em: 2010
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21. Biocomposites from high density biopolyethylene and curaua fibers / Biocompósitos a partir de biopolietileno de alta densidade reforçado por fibras de curauá
In this work, curaua fibers were used in the reinforcement of a high-density (HDPE) thermoplastic matrix. The polyethylene used in this study was obtained by polymerization of ethene produced from sugarcane ethanol. This polymer, also called high-density biopolyethylene (HDBPE), was prepared from a natural source material. The aim of the present study was to
Publicado em: 2010
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22. Study of plasticizer diffusion in a solid rocket motor´s bondline
Abstract: This work aims to determine the diffusion coefficient of the plasticizers dibutyl phthalate (DBP), dioctyl phthalate (DOP) and dioctyl azelate (DOZ) on the internal insulating layer of solid rocket motors. These plasticizers are originally present in the layers of rubber, liner and propellant, respectively. This species are not chemically bonded an
J. Aerosp. Technol. Manag.. Publicado em: 2009-12
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23. Estudo da tenacificação do poliestireno com elastômeros butadiênicos / Polystyrene toughening by butadiene elastomers
This Dissertation describes a study about the toughening of polystyrene with different types of polybutadiene (high-cis, low-cis and styrene - butadiene diblock or triblock copolymers). These materials (High Impact of PolyStyrene HIPS) were performed by melt blending. The mechanical properties (hardness, tensile strength and impact strength); morphology and
Publicado em: 2009
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24. Estudos do fenomeno de difusão de plastificantes em propelente composito a base de polibutadiero hidroxilado utilizado em motores foguete / A study of diffusion of plasticizer in a solid propellant based on hydroxyl-terminated polybutadiene
Os propelentes compósitos à base de polibutadieno líquido hidroxilado (PBLH) utilizados na produção dos motores foguete a propelente sólido (MFPS), desenvolvidos no Instituto de Aeronáutica e Espaço (IAE), podem sofrer alterações em suas propriedades físicas devido ao processo de difusão de plastificantes entre as interfaces das camadas de propel
Publicado em: 2009