Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.2/4416
Título: On the mobility of dialkyl adipates by PFGSE NMR, computer simulations and other property measurement methods
Autor: Ascenso, José R.
Fareleira, João M. N. A.
Rubio, Guilherme
Martins, Luís A. M.
Diogo, João C. F.
Caetano, Fernando J. P.
Palavras-chave: Dialkyl adipates
Diffusion
Self-diffusion coefficients
PFGSTE method
NMR
Data: 22-Set-2014
Editora: Fundación General de la Universidad de Alcalá
Citação: Ascenso, José R.; [et al.] - On the mobility of dialkyl adipates by PFGSE NMR, computer simulations and other property measurement methods. In GERMN 2014. Biennial Meeting of the Nuclear Magnetic Resonance Group of the Spanish Royal Society of Chemistry, 7, Alcalá de Henares, 2014 / Iberian NMR Meeting, 4, Alcalá de Henares, 2014 / Ibero-American NMR Meeting, 6, Alcalá de Henares, 2014 - "GERMN 2014" [Em linha]. Alcalá de Henares : Fundación General de la Universidad de Alcalá, 2014. 1 Poster (PO-54)
Resumo: Dialkyl adipates are a class of esters materials used as components of lubricants and plasticizers. Diffusion of plasticizers in polymers is a complex process that is difficult to study [1]. As a contribution to understand this phenomenon, the self-diffusion coefficients of five dialkyl adipates (dimethyl, diethyl, dipropyl, dibuthyl and bis(2-ethylhexyl)) were measured by the PFGSTE method in the temperature range 20 to 60ºC. It was shown that these compounds follow the Stokes-Einstein equation [2]. In effect, the self-diffusion coefficients change linearly with T.η-1(η is the viscosity). The dependence of the activation energies for self-diffusion is discussed in terms of size and branching of the alkyl chains of the adipates. Molecular dynamics (MD) simulations were done for these sytems in order to predict the diffusion coefficients as a function of temperature [3]. Acknolwedgements: This work was supported by the Strategic Projects PEst-OE/QUI/UI0100/2011 and PEst-OE/QUI/ UI0100/2013, both funded by Fundação para a Ciência e a Tecnologia (FCT, Portugal). We thank also FCT for funding the NMR facility through Project RECI/QEQ-QIN/0189/2012. References: [1] Rahman M.; Brazel C. S., Prog. Polym. Sci. 2004, 29, 1223–1248. [2] Price W.S, NMR Studies of Translation Motion, Cambridge University Press, Cambridge, 2009. [3] Pereira, L. A. M.; Martins, L. F. G.; Ascenso, J. R; Morgado, P.; Ramalho, J. P. P.; Filipe, E. J. M., J. Chem. Eng. Data 2014, accepted for publication.
Descrição: Encontro realizado em Alacalá de Henares (Madrid), de 22 a 25 de Setembro de 2014
Peer review: no
URI: http://hdl.handle.net/10400.2/4416
http://www.germn2014.com/imgdb/archivo_doc6888.pdf
Aparece nas colecções:Ciências e Tecnologia - Comunicações em congressos, conferências, seminários/Communications in congresses, conferences, seminars

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