Surface characterization of lignin materials by means of inverse gas chromatography

Abstract

Inverse gas chromatography was successfully used for the determination of Hansen solubility parameters (HSPs), as well as other surface parameters. Values of dispersive, polar and hydrogen bonding components of solubility parameters are used in the prediction of the behaviour of exemplary pharmaceutically active material in real mixtures, e.g. interactions with excipients. Values of HSPs are close to that obtained from additive method of the Hoftyzer/van Krevelen procedure. However, the second one can only be calculated if the structure of examined material is known. It is impossible to estimate it for mixtures or species which have unknown structures. In such a case, the use of inverse gas chromatography is suggested. Surface ability of lignin materials to various types of interaction might be also expressed by means of inverse gas chromatography derived surface parameters, including its heterogeneity. The examined materials were also characterized by DSC and TG-MS techniques.