Abstract
Polymeric character and micell structure of coal are reviewed from view point of interaction between solvent and coal. Molecular weight per crossed unit of coal is of important factor determining not only chemical structure but physical properties of coal. The cohesive energy density i. e. solubility parameter of coal is estimated from solvent extraction or swelling equilibrium with solvent . It is stressed the fact that the physico chemical behaviours described above are correlated with compatibility between coal, coal blends and solvent.
