Isoprene
Mostrando 1-12 de 79 artigos, teses e dissertações.
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1. Synthesis and characterization of isoprene oligomers to compare different production chemical processes
Abstract Three methods to obtain isoprene oligomers were evaluated: chemical degradation of non-vulcanized coagulated natural rubber; chemical degradation of natural rubber latex; and oligomerization of the isoprene monomer. The products were characterized by infrared spectrometry (FTIR), nuclear magnetic resonance (NMR) and size-exclusion chromatography (S
Polímeros. Publicado em: 18/03/2019
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2. Characterization of additives in NR formulations by TLC-IR (UATR)
Abstract It is a well-established fact that rubber accelerator is essential to provide solution in different sectors. However, there is a reversal process which can reduce the material performance. Sulfur accelerators donors and organic peroxides have been presented as a solution to the problem. The methodology development that can separate or characterize
Polímeros. Publicado em: 10/07/2018
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3. Molecular Modeling, Structural Analysis and Evaluation of 1-Deoxy-D-Xylulose-5-Phosphate Reductoisomerase (DXR) as a Putative Drug Target For Theileria Parva
ABSTRACT The apicomplexan parasite Theileria parva, the causative agent of ECF, is an important pathogen affecting both domestic and wild animals, causing major economic losses in the world. Problems such as high cost of drugs, development of resistance, and absence of effective vaccines prevent effective combating of the pathogen. Thus, it is necessary to e
Braz. arch. biol. technol.. Publicado em: 14/06/2018
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4. AVALIAÇÃO DA EFICIÊNCIA DO MÉTODO TO-15 PARA DETERMINAÇÃO DE COMPOSTOS ORGÂNICOS VOLÁTEIS EM CONDIÇÕES TÍPICAS DE AMBIENTE URBANO
The efficiency of U.S.EPA TO-15 Method was evaluated under typical conditions of an urban environment with natural and anthropic emission sources. The performance criteria which should be met for a system to qualify, were fulfilled: a detection limit of ≤0.2 ng for all target compounds, replicate precision for a calibration standard and ambient samples wit
Quím. Nova. Publicado em: 2016-12
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5. Diurnal Pattern of Leaf, Flower and Fruit Specific Ambient Volatiles above an Oil Palm Plantation in Pará State, Brazil
Oil palm plantations are rapidly expanding in the tropics because of insatiable global demand for fruit oil to be used in food, biofuels and cosmetics. Here we show that three tissue-specific volatiles can be quantified in ambient air above an African-American hybrid oil palm plantation in Brazil and linked photosynthesis (isoprene), floral scent (estragole)
J. Braz. Chem. Soc.. Publicado em: 2016-08
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6. Experimental comparative study of the histotoxicity of poly(lactic-co-glycolic acid) copolymer and poly(lactic-co-glycolic acid)-poly(isoprene) blend
Current treatments of craniosynostosis rely on the application of metal springs for cranial bone deviation. However, those metal springs demand a second surgical procedure for their removal. An attractive alternative would be the substitution of metal for bioresorbable polymers in the composition of the springs. The addition of poly(isoprene), PI, to poly(la
Polímeros. Publicado em: 12/09/2014
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7. Degradation of non-vulcanized natural rubber - renewable resource for fine chemicals used in polymer synthesis
In the current scenario, there is growing interest in the products of degradation of rubber (natural and synthetic) for specific applications in different industry sectors, whose benefits in replacing conventionally used products are mainly related to sustainability. Since the degradation products of rubber can be used in different areas, several research gr
Polímeros. Publicado em: 20/08/2013
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8. Analysis of Poly(Lactic-co-Glycolic Acid)/Poly(Isoprene) Polymeric Blend for application as biomaterial
The application of renewable raw materials encourages research in the biopolymers area. The Poly(Lactic-co-Glycolic Acid)/Poly(Isoprene) (PLGA/IR) blend combines biocompatibility for application in the health field with excellent mechanical properties. The blend was obtained by solubilization of polymers in organic solvents. To investigate the polymer thermo
Polímeros. Publicado em: 2013
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9. Study of in vitro degradation of poly (1,4-trans-isoprene)(in nature)and in dental cones / Estudo da degradaÃÃo microbiana in vitro do Poli (1,4-trans-isopreno) (in natura) e em cones dentÃrios.
Os cones de guta-percha usados em endodontia, compostos de poli (1,4-trans-isopreno), ZnO e/ou BaSO4 e ceras/resinas, foram feitos para durar a vida inteira nos canais radiculares por eles preenchidos. Entretanto, existem evidÃncias de que esses materiais sofrem degradaÃÃo com o decorrer do tempo de obturaÃÃo intensificada quando existem infecÃÃes por
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/09/2012
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10. Emission of isoprene by eucalyptus and its influence in the formation of tropospheric ozone / Emissão de isopreno por plantações de eucalipto e sua influência na formação de ozônio troposférico
Este é o primeiro estudo de medida de compostos orgânicos voláteis leves (C$_2$-C$_6$) realizado em uma plantação comercial de eucalipto do Vale do Paraíba. As coletas foram efetuadas numa área pertencente à empresa Fibria, localizada na cidade de Caçapava. Com o objetivo principal de estudar a influência do isopreno na formação de ozônio tropos
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/10/2011
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11. Telomerization of isoprene and methanol assisted by palladium-chiral phosphine and/or-chiral amine complexes
A reação do isopreno em presença de metóxido de sódio e de quantidades catalíticas de compostos de paládio(I1) associados a uma série de fosfinas e aminas mono e bidentadas quirais produz essencialmente o telômero l-met6xi-2,6-dimetil-2,7-octadien2o e o dímero 2,7-dimetil- 1,3,7-octatrieno 4. A formação do dímero e do telômero pode ser controla
Publicado em: 2011
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12. Efeito antioxidante de componentes do lÃtex da seringueira e mangabeira sobre a degradaÃÃo termo-oxidativa do POLI(1,4-CIS-ISOPRENO) sintÃtico / Antioxidant effect of components of the latex from seringueira (Hevea brasiliensis)and mangabeira(Hancoria speciosa)on thermo-oxidative degradatiion of synthesic Poly (1,4-cis-isoprene
O presente trabalho à dividido em duas partes: A primeira està relacionada com o isolamento dos componentes nÃo-isoprÃnicos do lÃtex da borracha natural (BN) da seringueira (Hevea brasiliensis) e mangabeira (Hancornia speciosa) por centrifugaÃÃo. Na primeira centrifugaÃÃo foi isolada a fase serum (MAT 1). A fase borracha foi tratada com o surfactant
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/01/2008