Intermolecular interactions between polyarylenephthalides surface and organic compounds of different nature by inverse gas chromatography data

Abstract

Polyarylenephthalides are a promising class of polymeric materials. They are soluble in organic solvents, but remain resistant to water, as well as to acids and bases. All this makes polyarylenphthalide promising materials for the formation of films on surfaces. However, for this it is necessary to first study the ability of polyarylenephthalides to different intermolecular interactions, as well as the polarity of their surface.Therefore, it is of interest to use the inverse gas chromatography method for studying the adsorption properties of the surface of polyarylenephthalates, as well as the evaluation of its conditional polarity. Two polymers of the class of polyarylenephthalides were used as the studied samples: chlorinated (in position 4) poly phthalidylidenefluorene) (OPS-236) and poly (phthalidylidene diphenyl) (PE-259). They are distinguished by the presence of a methylene group between two benzene rings. Inert solid support Chromaton NAW was used as a solid substrate for the deposition of polyarylenphthalide films. The application was carried out from chloroform by evaporation of the solvent at a temperature of 40 ° C. The amount of the applied polymer was 1% by weight of the inert carrier. The study was conducted by the method of inverse gas chromatography. Samples were introduced as diluted vapor-air mixtures at the limit of the detector sensitivity. This made it possible to measure the retention parameters in the Henry region and consider the interactions between sorbate molecules to be negligible. The relative conditional polarity of the surface and the contributions of various intermolecular interactionsto adsorption free energy were estimated by the method of linear free energy relationship (LFER). From the obtained LFER-coefficients, the contributions of intermolecular interactions to the adsorption energy were calculated, and the relative conditional polarity of the surface was also estimated. The dispersion and specific component of the Helmholtz free energy of adsorption was calculated by the Dong method. It has been established that adsorbents based on polyarylenephthalides are able to act as stationary phases for chromatography. It is shown that polyarylenephthalide films are capable of both dispersion and various specific interactions with organic molecules. The surface of polyarylenephthalides can be attributed to stationary phases of medium polarity, more polar than porous polymers based on styrene and divinylbenzene and less polar than silica gels.