The rheological properties of concentrated aqueous solutions of water-soluble polyesters prepared by copolycondesation of dimethyl terephthalate

iso-phthalic acid

dimethyl 5-sodiosulfoisophthalate with ethylene glycol

have been investigated.The concentrated aqueous solutions (30%) of water-soluble polyesters show a weak shear-thickening feature with flow index from 1.04 to 1.20.Their lgηa-τcurves show a linear feature

and the zero shear viscosity varies with molecular structure

molecular weight and temperature.Specially

the content of bis(2-hydroxyethyl)5-sodiosulfoisophthalate in molecular chains has a large effect on the viscosity of solutions.Ther viscosity-flow activation energy varies with molecular structure of the polymer and the shear rate in a range of 12.0-23.9kJ/mol.