Comparison of the intrinsic viscosity and inverse gas chromatography techniques in determination of the exchange enthalpy and entropy parameters

Abstract

The χ1-interaction parameters of poly(dimethyl siloxane) with methyl ethyl ketone at very low polymer concentration were determined by means of intrinsic viscosity (IV) measurements at several temperatures. The χt∞-total interaction parameters of the same system at infinitely high polymer concentration were also determined using inverse gas chromatography (i.g.c.) technique around the same temperature range. Then, exchange enthalpy, X12, and entropy, Q12, parameters in the Flory's equation of state theory were determined from the obtained interaction parameters. Both X12 and Q12 parameters obtained by IV are lower than those found by i.g.c.. © 1997 Elsevier Science Ltd.