Avaliação da interferência de salinidade e dureza da água no processo de micelização com sabão base Evaluation of interference of salinity and water hardness in micellization process with the anionic surfactant SB

The use of animal fat for soap industry is being increasingly emphasized due to the fact that this present a low cost. The tallow is a raw material of great relevance in Brazil, since this is a co-product of the meat, which is produced on a large scale in the country. The addition of different surfactants formulations presents adverse behaviors when it is analyzing the process of micellization. This study aims to analyze the effect of additives in this process: the addition of an electrolyte, which it used KCl; influence of hard water and a complexing agent in the formulation of solutions. Analyzes were performed using the drop weight method. The results were consistent with the literature. The values of c.m.c. showed that the presence of the electrolyte decreases the CMC because this enabling a smaller electrostatic repulsion between molecules of surfactant. Already hard water caused an increase in the c.m.c, a fact that might be explained by the neutralization of surface-active molecules by metals contained in water, this value of c.m.c. was decreased by the addition of EDTA to complex the metals that interfere in the process of micellization.