화학공학소재연구정보센터
Journal of Membrane Science, Vol.475, 545-551, 2015
A new prediction method for organic liquids sorption into polymers
A new prediction method for sorption of low molecular organic liquids (non solvents) in polymers is presented. It was derived from the gravimetric data for sorption of linear and cyclic alkanes, aromatics and alcohols into various kinds of polymers (glassy polystyrene, robbery polyclimeLhylsiloxane, sernicrystalline low-density polyethylene, ion exchange Nation, and copolyrneric poly(styrene-butadiene-styrene) in temperature range 5-50 degrees C. Our method is based on a normalised function phi Q(t) evaluated from series of the equilibrium mass swelling degrees Q(m) of a model liquid in one polymer at each temperature from the indicated temperature interval to the corresponding (2, at the highest temperature of this interval. A knowledge of the proper function 5,0(t) for given polymer enables to predict a sorption of any other liquid with the same properties or interactions with given polymer in given temperature range just from a knowledge of a single experimental Q(m) value at any temperature horn the indicated temperature interval. The steepest temperature dependent normalised function phi Q(t) exhibited LOPE+ liquid systems. Contrarily, POEMS +liquid systems were practically temperature independent. The thermodynamic analysis of the sorption process in studied polymer-liquid systems comprised evaluation of the appropriate values of the sorption enthalpy Delta H-s and the sorption entropy The values of the resulting Gibbs energy of sorption Delta(s)G were negative in all cases and thus confirmed the spontaneity of liquids sorption in polymers over the whole temperature range. (C) 2014 Elsevier B.V. All rights reserved.