resumo
Experimental data for density, viscosity, refractive index and sound speed of 11 glycols and glymes were measured in the temperature range between (283.15 and 373.15) K and at atmospheric pressure. The compounds evaluated include ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TriEG), tetraethylene glycol (TeEG), ethylene glycol ethyl ether (EGEE), diethylene glycol methyl ether (DEGME), diethylene glycol dimethyl ether (DEGDME), diethylene glycol ethyl ether (DEGEE), diethylene glycol diethyl ether (DEGDEE), triethylene glycol dimethyl ether (TriEGDME), and tetraethylene glycol dimethyl ether (TeEGDME). Additionally, derivative properties, such isobaric thermal expansion coefficient and isentropic compressibilities were also estimated and discussed. The compounds evaluated were selected to evaluate the impact of molecular structure changes on their thermophysical properties. Effects like the increase in the number of ethoxy groups, shown to lead to an increase of the density, molar volume, viscosity, and refractive index, or the loss of the hydroxyl groups through the substitution of the hydroxyl groups hydrogen by a methyl or ethyl group, shown to lead to a significant decrease on the density, viscosity, and sound speed, are evaluated and discussed.
palavras-chave
EXCESS MOLAR VOLUMES; AQUEOUS BINARY-MIXTURES; PLUS ETHYLENE-GLYCOL; DIMETHYL ETHER-WATER; TERT-BUTYL ETHER; DIETHYLENE GLYCOL; 298.15 K; REFRACTIVE-INDEXES; TETRAETHYLENE GLYCOL; TRIETHYLENE GLYCOL
categoria
Thermodynamics; Chemistry; Engineering
autores
Carvalho, PJ; Fonseca, CHG; Moita, MLCJ; Santos, AFS; Coutinho, JAP
nossos autores
agradecimentos
This work was developed in the scope of the projects CICECO-Aveiro Institute of Materials (ref FCT UID/CTM/50011/2013) and financial supported under FCT projects CQE-FC-UL (ref FCT UID/QUI/00100/2013) and CQB- FC-UL (ref FCT UID/MULTI/00612/2013), financed by national funds through the FCT/MEC and cofinanced by FEDER under the PT2020 Partnership Agreement. A.F.S.S. and P.J.C. also acknowledge University of Lisbon for granting sabbatical leave of absence in the academic year 2014/2015 and FCT for the postdoctoral grant SFRH/BPD/82264/2011, respectively.