Influence of the ratio of polyamidbezimidazole to aromatic polysulphone on the base of diphenylpropane and 4,4′-diphenylolsulphone on the process of separation of bicomponent polymer from dimethylformamide containing LiCl was investigated. Enthalpy of interaction of polymeric components with solvent was measured. It was observed that a mixture with 25 % of polysulphone had the least enthalpy value and so the greatest component interaction.