APPARENT VISCOSITY OF BINARY AND TERNARY SYSTEMS OF TRAGACANTH, GUAR GUM AND METHYLCELLULOSE AT SEMIDILUTE RANGE OF CONCENTRATION

摘要

The viscosity of the binary and ternary systems of tragacanth (T), guarn(G) and methylcellulose (MC) was obtained by means of a rotational viscom-neter in the range of concentration from 1 to 10 g/L at 25, 35, 45 and 55C. Thenmodeling was based on polymer concentration, temperature and shear rate.nThe viscometric parameters, flow and consistency indices were evaluated as anfunction of the cited variables, obtaining the corresponding correlations.nInteractions between polymers are hypothesized because of its structure andnmolecular weight. An interaction parameter Dhij was calculated for modeling.nAs expected, in all the cases, the apparent viscosity decreases with tempera-nture and it was introduced in the proposed models for T–G and G–MC systems.nSynergistic effects were found for T–G in all the cases and G–MC when Gnconcentration was higher than MC concentration. These results could suggestnthat interactions between MC and G molecules are generated.