The concentration dependence of the ‘zero-shear’ specific viscosity for a commercial hydroxyethylmethylcellulose (HEMC) in water at several temperatures

This short paper presents preliminary results on the ‘zero-shear’ specific viscosity η_sp0 of a commercial hydroxyethylmethylcellulose (Tylose MH-4000) in water, at the temperatures 10, 25 and 40·5°C, over a wide range of concentrations. At the two higher temperatures, two regions are found in the plot of logCη]₀ against logη_sp0 with a C^*η]₀ value of about 2·5. This is consistent with the behaviour of other random-coil polymers. At 10°C however, there is an interesting ‘upward shift’ in this plot in the dilute region. It is suggested that this is related to the different degree of hydration of the oligo(ethyleneoxide) side chains at this temperature.