RHEOLOGICAL EQUATIONS FROM MOLECULAR NETWORK THEORIES

Two rheological models are proposed by assuming two different mechanisms for the effect of the rate of strain on the kinetics of the network. The experimental data on three fluids are used to test the models in various flow situations. For suddenly changing flow experiments model A is inadequate. Model B however appears to be the only rheological equation which can fit simultaneously the steady shear, complex viscosity, stress growth, and stress relaxation functions. An interpretation of the stress growth and relaxation phenomena is given in the light of the modified theory.