Viscous and thermal properties of a phenolic resin (Part I) and a polymeric isocyanate (Part II), and their blends were investigated by using rotational viscometry. The elastic properties of the blends were investigated by means of a jet thrust technique, using a straight tube. The rheological and thermal properties of the blends were dependent on the blend composition. Although both materials are Newtonian liquids, their blends exhibit non-Newtonian liquid flow behavior and elasticity. A thermo-reaction has been observed and investigated after mixing the two parts.