The influences of temperature

melting time

polyester content and molecular weight on the apparent viscosity for the melt of poly(ether/ester) block copolymers were studied by means of Instron 3211 capillary rheometer. It was shown in experimental results that the melt was a pseudoplastic and non-Newtonian fluid

but the variation of apparent viscosity for the copolymers with the shear rate was not in agreement with the power law model. The apparent viscosity of the poly(ether/ester) melts increased with the content and the molecular weight of the polyether segments.It was shown that the relationship between the zero-shear viscosity obtained according to Spencer-Dillon equation and temperature obeys Andrade equation.The activation energies of viscous flow for the ploy (ether/ester) block copolymers were 39.4

84.2and 169.3kJ/mol

as the contents of polyester segments were 30%

45%and 65%

respectively.