Water activity of aqueous solutions of ethylene oxide-propylene oxide block copolymers and maltodextrins

Brazilian Journal of Chemical Engineering

N. D. D. Carareto²  E. S. Monteiro Filho²  P. A. Pessôa Filho¹  A. J. A. Meirelles² 

[1] ,Universidade Estadual de Campinas Departamento de Engenharia de Alimentos Campinas SP ,Brazil

关键词: Water activity;    Excess Gibbs energy;    Phase equilibrium;    Flory-Huggins;    UNIFAC;   

DOI  :  10.1590/S0104-66322010000100015

来源: SciELO

【 摘 要 】

The water activity of aqueous solutions of EO-PO block copolymers of six different molar masses and EO/PO ratios and of maltodextrins of three different molar masses was determined at 298.15 K. The results showed that these aqueous solutions present a negative deviation from Raoult's law. The Flory-Huggins and UNIFAC excess Gibbs energy models were employed to model the experimental data. While a good agreement was obtained with the Flory-Huggins equation, discrepancies were observed when predicting the experimental behavior with the UNIFAC model. The water activities of ternary systems formed by a synthetic polymer, maltodextrin and water were also measured and used to test the predictive capability of both models.

【 授权许可】

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