Poliuretana derivada de óleos vegetais exposta ao intemperismo artificial

Almeida, A. E. F. S.; Ferreira, Olga

doi:10.1590/s0104-14282006000300017

Cited by 5 publications

(6 citation statements)

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“…However, both, solar radiation and the high temperature may accelerate the degradation of the polymers PCL and β-cyclodextrin releasing the active ingredient more quickly. It is known that ultraviolet radiation acts as degradation agent of polymeric materials due to its association with photodegradation mechanism (ALMEIDA; FERREIRA, 2006). Probably, the rupture of the polymer and the exposition of the active ingredient occurred gradually.…”

Section: Discussionmentioning

confidence: 99%

“…It is a cyclic polymer which contains seven unities of glucose joined in α-1,4 obtained through enzymatic degradation of the amylum (BOBBIO; BOBBIO, 2001). Another biodegradable polymer, poly-ε-caprolactone (PCL), has been studied by researchers not only in releasing systems of pharmaceutical drugs (SCHAFFAZICK et al, 2006) but also in civil building industry (ALMEIDA; FERREIRA, 2006). PCL is an aliphatic polyester obtained by polymerization of ε-caprolactone in the presence of aluminum isopropoxide (CHIELLINI; SOLARO, 1996).…”

Section: Introductionmentioning

confidence: 99%

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Efficiency of neem oil nanoformulations to Bemisia tabaci (GENN.) Biotype B (Hemiptera: Aleyrodidae)

et al. 2012

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The nanotechnology, through encapsulation of active ingredients, has showed an important way to avoid problems with quickly degradation of the pesticide molecules. Thus, neem (Azadirachta indica) oil nanoformulations containing β-ciclodextrin and poli-ε-caprolactone (PCL) were tested as to their control efficiency against eggs and nymphs of Bemisia tabaci (Genn.) biotype B reared in soybean. The Lethal Concentration (LC 50 ) was estimated using a commercial neem oil (Organic Neem ® ) on firstinstar nymphs to establish the adequate volume of the nanoformulations per treatment. After that, they were sprayed on eggs and first-instar nymphs in laboratory and greenhouse and on third-instar nymphs in greenhouse. The commercial neem oil and distilled water were used as controls. Egg viability was not affected by any treatment. Among six nanoformulations, only one was efficient against the firstinstar nymphs in laboratory conditions. However, its effective period was not increased as expected. In greenhouse, first-instar nymphs were more affected by two nanoformulations which were significantly different of the commercial neem oil -the most effective one. No mortality differences among the formulations in the third-instar test were observed. The nanoformulations were less efficient to control the B. tabaci biotype B nymphs than the commercial neem oil. Key words: Whitefly, botanical pesticide, nanotechnology, β-ciclodextrin, poli-ε-caprolactone ResumoA nanotecnologia, através do encapsulamento de ingredientes ativos, tem-se revelado uma importante estratégia para evitar problemas com a rápida degradação de moléculas inseticidas. Assim, nanoformulações à base de óleo de nim (Azadirachta indica) utilizando os polímeros β-ciclodextrina e poli-ε-caprolactona (PCL) foram testadas quanto a sua eficiência de controle de ovos e ninfas de Bemisia tabaci (Genn.) biótipo B mantidas em soja. Foi estimada a CL 50 utilizando uma formulação comecial de óleo de nim (Organic Neem ® ) sobre ninfas em 1º ínstar da qual se estipulou o volume das nanoformulações a serem utilizadas por tratamento. Depois disso, os tratamentos foram aplicados sobre ovos e ninfas de 1º ínstar em laboratório e em casa de vegetação e sobre ninfas de 3º ínstar em casa de vegetação. O óleo comercial e água destilada foram utilizados como controles. A viabilidade dos ovos não foi afetada por qualquer dos tratamentos. Das seis formulações testadas, somente uma delas mostrouse eficiente para ninfas de 1º ínstar em condições de laboratório, embora não tenha apresentado aumento

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Efficiency of neem oil nanoformulations to Bemisia tabaci (GENN.) Biotype B (Hemiptera: Aleyrodidae)

et al. 2012

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“…In this usage, the polymeric material protects concrete, preserving its integrity. However, Almeida and Ferreira 18 point out that properties alteration will be detected in these polymeric materials under solar radiation action combined with oxygen.…”

Section: Literature Reviewmentioning

confidence: 99%

Accelerated artificial aging of particleboards from residues of CCB treated Pinus sp. and castor oil resin

et al. 2013

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Tests simulating exposure to severe weather conditions have been relevant in seeking new applications for particleboard. This study aimed to produce particleboards with residues of CCB (chromium-copper-boron oxides) impregnated Pinus sp. and castor oil-based polyurethane resin, and to evaluate their performance before and after artificial accelerated aging. Panels were produced with different particle mass, resin content and pressing time, resulting eight treatments. Particles moisture and size distribution were determined, beyond panel physical and mechanical properties, according to NBR14810-3: 2006. After characterization, treatments B and G (small adhesive consumption and better mechanical performance, respectively) were chosen to artificial aging tests. Statistical results analysis showed best performances were achieved for waterproof aged samples, of both B and G treatments. As example, in treatment B, MOR and MOE values were 23 MPa and 2,297 MPa, samples before exposure; 26 MPa and 3,185 MPa, 32 MPa and 3,982 MPa for samples after exposure (non-sealed and sealed), respectively.

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“…Embora existam artigos já publicados sobre síntese e propriedades de poliuretanas de óleo de mamona [6][7][8][9] , nenhum estudo foi até o presente momento dedicado à avaliação da dietanolamina/trietanolamina como extensores de cadeia e as respectivas propriedades das poliuretanas obtidas em circuitos eletroeletrônicos.…”

Section: -Preparação De Resinas De Poliuretana à Base De óLeo De Mamounclassified

Preparação de Resinas de Poliuretana à Base de Óleo de Mamona e Dietanolamina e sua Aplicação em Circuitos Eletroeletrônicos

Cardoso

Balaban

2013

Polímeros

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Resumo: O óleo de mamona é um óleo vegetal que permite várias reações em seus grupos funcionais hidroxila. O ácido ricinoleico (ácido 12-hidroxioleico) compõe cerca de 90% dos ácidos graxos presentes, enquanto os outros 10% são não hidroxilados. Este trabalho teve como objetivo obter polióis a partir de misturas do óleo de mamona tipo I (OM) com dietanolamina (DEA), visando elevar o grau de reticulação dos produtos finais, para uso em circuitos eletroeletrônicos. A intenção de se introduzir a dietanolamina nas formulações de resina de poliuretana advém das dificuldades apresentadas por empresas do ramo na aquisição da trietanolamina, que atualmente se encontra sob controle de órgãos federais. Análises químicas e espectroscópicas evidenciaram a obtenção de polióis com índice de hidroxila entre 230 e 280 mgKOH/g. A cinética da reação de poliadição entre os polióis resultantes e o isocianato de isoforona (IPDI) foi acompanhada pelas mudanças nas propriedades reológicas do meio, a 60 °C. As poliuretanas apresentaram propriedades compatíveis com as dos produtos atualmente disponíveis no mercado, obtidos com trietanolamina (TEA). Palavras-chave: Óleo de mamona, dietanolamina, poliuretana, propriedades reológicas, propriedades elétricas, dureza. Preparation of Polyurethane Resins Based on Castor Oil and Diethanolamine and their Application in Electronic CircuitsAbstract: Castor oil (CO) is a vegetable oil that allows for multiple reactions in their hydroxyl functional groups. Ricinoleic acid (12-hidroxioleic acid) comprises about 90% of the fatty acids present while the remaining 10% are not hydroxylated. The aim of the present work was to obtain polyols from castor oil (CO) and diethanolamine (DEA), to improve the crosslinking degree of final products to be used in electronic circuits. The use of diethanolamine instead of triethanolamine in the polyurethane resin formulation is of special interest of companies, due to the difficulties in acquiring triethanolamine, which is controlled by the Brazilian Army. Chemical and NMR characterization showed that the polyol obtained had a hydroxyl number between 230 and 280 mgKOH/g. The kinetics of the polyaddition reaction from polyols and isophoronediisocyanate (IPDI) was evaluated employing rheological assays at 60 °C. The polyurethane based on DEA had compatible properties with the commercial products obtained from triethanolamine (TEA).

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Poliuretana derivada de óleos vegetais exposta ao intemperismo artificial

Cited by 5 publications

References 1 publication

Efficiency of neem oil nanoformulations to Bemisia tabaci (GENN.) Biotype B (Hemiptera: Aleyrodidae)

Efficiency of neem oil nanoformulations to Bemisia tabaci (GENN.) Biotype B (Hemiptera: Aleyrodidae)

Accelerated artificial aging of particleboards from residues of CCB treated Pinus sp. and castor oil resin

Preparação de Resinas de Poliuretana à Base de Óleo de Mamona e Dietanolamina e sua Aplicação em Circuitos Eletroeletrônicos

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