Rheological behaviour of solutions of poly(2-hydroxyethyl methacrylamide) in glycerine

The rheological behaviour of dilute and semidilute solutions of poly(2-hydroxyethyl methacrylamide) in glycerine is described, emphasising the study of the variation of both the zero shear rate viscosity, η0, and the steady-state compliance function, Je0, with concentration. Shear rate fields, above a critical value, may promote molecular tight ‘structures’ that enhance the viscosity of the semidilute solutions and, as a result, these systems exhibit shear-thickening behaviour. However, the dilute solutions display shear-thinning behaviour and obey the Cox–Merz rule. The flow transients appearing after either application of a constant shear rate or cessation of flow were studied for semidilute solutions. The shear-thickening behaviour of these solutions is interpreted in terms of the formation of hydrogen bonds between the acrylamide groups and the carbonyl groups of different chains.