A química dos óleos e gorduras : uma abordagem para o ensino médio

Trabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Instituto de Química, 2013.O uso de óleos e gorduras pelo ser humano é de crucial importância há milênios. Os primeiros usos foram para iluminação, produção de sabão e alimentação. Nos dias atuais, além das citadas aplicações, estes materiais têm sido uma excelente alternativa para substituir os insumos fósseis em vários setores, como polímeros, combustíveis, tintas de impressão, lubrificantes, entre outros. Apesar da citada importância histórica e tecnológica destes materiais, a abordagem deste tema no Ensino Médio ainda é bastante limitada. Este trabalho buscou apresentar e discutir os principais conceitos químicos envolvidos na área de oleoquímica, descrevendo os principais métodos de extração de óleos e gorduras de fontes vegetais e animais. Além disso, utilizou-se a abordagem CTS no Ensino Médio em conjunto com a teoria da transposição didática e da experimentação em química para propor materiais de ensino que possam auxiliar professores e alunos a entenderem a química e a importância dos óleos e gorduras para a sociedade

Production of additives with antimicrobial activity via tandem hydroformylation-amine condensation of soybean fame using an ionic liquid-based biphasic catalytic system

A biphasic catalytic system based in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate was employed for tandem hydroformylation-amine condensation reactions of soybean FAME using HRhCO(PPh3)3 as the catalyst precursor and n-butylamine. Using a tenfold excess of the ligand PPh3, the presence of the ionic liquid increased the selectivity for imine if compared to the reaction carried out under similar conditions, but in homogeneous media.The yield for imine reached 75% after 24 h. On the other hand, in the absence of a PPh3 excess, the effect of using the ionic liquid was opposite and the selectivity for imine decreased. This supposedly occurred due to the generation ofN-heterocyclics carbenes, which would coordinate to Rh to form species active for parallel and/or consecutive reactions. When an excess PPh3 is used, it suppress the carbenes coordination, maintaining the Rh complex in a form active for hydroformylation.The obtained imine products presented remarkable antimicrobial activity towards a set of fungi and bacteria commonly present in fuel storage tanks

Síntese de novos derivados de biodiesel de soja via reação de carbonilação em sistema bifásico

Dissertação (mestrado)—Universidade de Brasília, Instituto de Química, 2010.Com o objetivo de promover melhorias em algumas propriedades, como a estabilidade oxidativa, a viscosidade e o ponto de entupimento de filtro a frio, foi realizada neste trabalho a modificação de biodiesel de soja por meio da reação de hidroformilação em um sistema catalítico bifásico. Para isto, líquidos iônicos (LI´s) derivados do cátion 1,3-dialquilimidazólio foram empregados como solventes para o complexo HRhCO(PPh3)3, o precursor catalítico para a reação. Foram estudados os efeito da presença do ligante trifenilfosfina (PPh3) no meio reacional e do emprego de diferentes LI’s na conversão e seletividade da reação. Além disso, foi investigada a estabilidade oxidativa do produto obtido e o reciclo da fase iônica para seguidas reações. Os resultados obtidos mostraram que a presença de PPh3 no meio reacional promove um aumento da seletividade para aldeídos por estabilizar o ródio na forma do complexo, que é ativo para a formação desse produto. Além disso, a presença da fosfina evita a formação de nanopartículas, que catalisam reações paralelas. A solubilidade dos produtos obtidos nos diferentes LI´s é o fator determinante para a perda de seletividade do sistema. Utilizando o BMI.NTF2, em que os produtos são mais solúveis, observou-se uma diminuição da seletividade devido a reações consecutivas que ocorreram rapidamente por causa do maior contato do catalisador com os substratos. O sistema com o BMI.PF6 apresentou melhores seletividades devido a menor solubilidade do aldeído neste LI, evitando que produtos de reações consecutivas fossem gerados. O produto de hidroformilação apresentou, de forma geral, estabilidade oxidativa baixa devido à reação de autoxidação dos aldeídos, que é acelerada pela presença do complexo de ródio que sofre lixiviação e passa para a fase orgânica. Ainda por causa do citado efeito de lixiviação, o reaproveitamento da fase iônica para consecutivas reações foi limitado. ______________________________________________________________________________ ABSTRACTThe aim of this work is to improve some technical features of soybean biodiesel, specially oxidative stability and cold properties. In order to improve these properties, this work developed an efficient two-phase catalytic system to modify soybean biodiesel by hydroformylation reaction in the presence of CO, H2 and HRhCO(PPH3)3 as catalytic precursor, which was evaluated with different reaction patterns. In this catalytic system, 1,3-dialkilimidazolium-based ionic liquids (IL´s) were used as solvent. Studies of the presence of PPh3, the effect of different IL, products oxidative stability and ionic phase recycle for several reactions were emphasized in this work. Results show that presence of PPh3 in the reaction system promotes higher selectivity to aldehyde because this ligand stabilizes rhodium as a metallic complex, avoiding nanoparticles to be generated during reaction process, which are active for consecutive and side reactions. Selectivity and conversion varies according to the IL employed. Products solubility in IL was crucial to evaluate the final product content. The lower selectivity for aldehyde was obtained using BMI.NTf2, due its higher solubility in this IL. Otherwise, the lower solubility of the products in BMI.PF6 promotes higher selectivity due the inefficient catalyst/product contact, avoiding consecutive reactions. Low oxidative stability occurred to hydroformylation product due the autoxidation reaction of aldehydes formed. Ionic phase recycle was inefficient because of the catalyst mass loss to the organic phase

Modificação de biodiesel de soja para produção de aditivo com atividade biológica

Neste trabalho foi empregado um sistema bifásico utilizando o líquido iônico 1-butil-3-metilimidazólio para as reações de hidroformilação-condensação com n-butilamina utilizando o complexo HRhCO(PPh3)3 como precursor catalítico para modificação de biodiesel de soja. Utilizando um excesso do ligante PPh3, a presença do líquido iônico aumentou a seletividade para a formação de imina quando comparada com a reação realizada em condições similares, mas em meio homogêneo. O rendimento para imina alcançou 75% após 24 h. Por outro lado, na ausência de um excesso de PPh3, o uso do líquido iônico teve efeito contrário para a reação, de forma que a seletividade para imina diminuiu. Este resultado foi atribuído à formação de carbenos N-heterocíclicos que se coordenam com o Rh para formar espécies catalíticas ativas para reações paralelas e/ou consecutivas. Quando um excesso de PPh3 é usado, ele impede a coordenação dos carbenos, mantendo o Rh na forma de complexo ativo para a hidroformilação. Os produtos nitrogenados obtidos apresentaram excelente atividade antimicrobiana contra fungos e bactérias comumente presentes em tanques de armazenamento de combustível. ________________________________________________________________________________________________ ABSTRACTA biphasic catalytic system using the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate was employed for tandem hydroformylation-amine condensation reactions of soybean biodiesel using HRhCO(PPh3)3 as the catalyst precursor and n-butylamine. When a tenfold excess of the ligand PPh3was employed, the presence of the ionic liquid increased the selectivity for imine if compared to the reaction carried out under similar conditions, but in homogeneous media. The yield for imine reached 75% after 24 h. On the other hand, in the absence of a PPh3 excess, the effect of using the ionic liquid was opposite and the selectivity for imine decreased. This supposedly occurred due to the generation of N-heterocyclic carbenes, which would coordinate to Rh to form species active for parallel and/or consecutive reactions. When an excess PPh3 is used, it suppresses the carbenes coordination, maintaining the Rh complex in a form active for hydroformylation. The obtained imine products presented remarkable antimicrobial activity towards a set of fungi and bacteria commonly present in fuel storage tanks

EFICIÊNCIA FLORA E BIOMASSA DOS FRUTOS DE COQUEIRO SOB DIFERENTES LÂMINAS DE IRRIGAÇÃO E NÍVEIS SALINOS

The Objective this work was to evaluate the interaction of the amount and salinity of irrigation water in the floral efficiency of the Green Dwarfish coconut tree, in the area of the coastal boards of the Northeast of Brazil. The study was driven in the experimental station of EMPARN, located in Parnamirim - RN, in the period of August of 2002 to September of 2003. The studied factors were four irrigation sheets, based on the evaporation of tank class "A" (30, 60, 90 and 120% of the evaporation of the tank) and four salinity levels in the irrigation water (0,1; 5,0; 10,0 and 15,0 dS.m-1). The experimental design was entirely random with subdivided portions and regression analysis with answer surface. The number of feminine flowers grows with the increment of the irrigation amount, reducing the negative effect of the applied saline levels. The relationship flower / picked fruit reduces with the increase of the saline levels, while the interaction of the largest irrigation sheets with the smallest saline levels results in a growth in the number of flowers emitted by picked fruits. The production in biomass of the fruits grows positively with the increase of the irrigation sheets and it reduces with the increase of the saline levels and the interaction of the smaller saline levels with the largest irrigation sheets produce the largest weights of registered fruits. As reaction the water with high salinity to the plant of the coconut tree answers with the increase of the efficiency of the bloomed related the crop of fruits, in other words, it emits less flowers to obtain the same production that in appropriate conditions of cultivation

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data