USE OF EMPIRICAL POLARITY PARAMETERS TO DESCRIBE POLYMER LIQUID INTERACTIONS - CORRELATION OF POLYMER SWELLING WITH SOLVENT POLARITY IN BINARY AND TERNARY-SYSTEMS

Dimroth and Reichardt polarity parameters E(T)(30) have been used, in a new approach, to quantitatively describe the swelling features due to polymer liquid interactions in binary and ternary systems. With the help of a polyurethaneimide (PUI) synthesized from polytetramethyleneglycol 650, sorption of pure liquids was first examined, and it was shown that a linear relationship between the molar swelling G(m) and the E(T)(30) values well fits the experimental data of each of the two series studied, i.e., aliphatic alcohols and linear ethers: G(m) = a + b E(T)(30). The slope value b, regarded as the sensitivity of the polymer to the liquid polarity, is 3 times higher for the aprotic series. The proposed correlation was further proved valid from the study of published results concerning nine binary systems polymer-liquid, whatever the polarity of the liquids in a given family (alcohols, esters, ketones, hydrocarbons) and the nature of the polymer. Finally, that method was tested on two types of PUI-alcohol-ether ternary systems, and it was found for each case that the partial molar swelling due to an homologous set of solvents can also be described by a similar law. (C) 1994 John Wiley and Sons, Inc.