Rheological modelling of binary and ternary systems of tragacanth, guar gum and methylcellulose in dilute range of concentration at different temperatures

Aqueous binary systems of tragacanth, guar and methylcellulose in dilute range of concentration up to 0.1% w/v were studied by means of capillary viscometry at 25.0, 35.0, 45.0 and 55.0 °C and were characterised through their intrinsic viscosities and the corresponding Huggins and Kraemer constants. The viscosity-average molecular weights were calculated and were according to previous reported data.Ternary dilute mixtures were studied as a function of polymer concentration and ratio. A model based on the kinematic viscosity was proposed for the ternary systems by means of the excess viscosity and corresponding parameters of interaction were determined. The model fitted satisfactorily the experimental data at the studied temperatures. Viscosity of the ternary systems increased with the intrinsic viscosity of the main polymer in mixture. The effect of the temperature (25–55 °C) in each obtained model is also discussed.