ИСТИНА

Free surface energy of films of amorphous polymers of different structure were determined by contact angle method. Polymers: polynorbornenes, polythrimethylsilylpropine (PTMSP), polymethylpentine (PMP) were synthesized and characterized in Topchiev Institute of Petrochemical Synthesis. Also commercial objects Teflons AF (Du Pont) and Hyflones AD (Solvay-Solexis) were studied. The correlations between the dispersive component of surface energy of polymer films and literature data about gas permeability of polymer membranes and fractional free volume of polymers were found. It is essential that the determination of surface energy, free volume and gas permeability were carried out for the same samples of synthetic polymers and in very close conditions of films formation. The correlations obtained were explained with positions of similarity of contact interactions between the solid spherical particles and centers of masses of polymer coils in polymer films. Wetting of PTMSP and PMP films with alcohol solutions was studied. Ethanol, propanol-1, propanol-2 and butanol-1 were used. The receding contact angle isotherms were analyzed to simulate the process of nanofiltration of liquid mixtures through the continual polymer membranes. For the all systems investigated the extremal dependences of interfacial «polymer-liquid» energy from alcohol concentration γLV(c) were observed. There is inverse relationship between the concentrations corresponding to extremum of γLV(c) dependence and alcohol solubility in water or fractional free volume of polymer. It was proposed that these concentrations correspond to the beginning of alcohol sorption in polymer film. So, the perspectives of contact angle measurements for prediction of polymer membrane efficiency with respect to gas and liquid transport were demonstrated.