Pyridine soluble portions of Upper Freeport (UF) and Illinois No.6 (IL) coals were mixed with N-methyl-2-pyrrolidinone (NMP). Annealings of the mixtures at 353K could produce stable gelleous materials. Changes in the viscoelastic properties of the samples with temperature were characterized by means of controlled strain oscillatory rheometory at temperatures between 223 and 273K during heating at a rate of 2K/min. The measured modulus of rigidity was resolved into storage and loss components, as a function of temperature and oscillation frequency. The complex viscosity was also evaluated and analyzed by using an existing viscosity model for associating suspensions.
