Temperature Dependent Partition Coefficients of Cyclohexylamine and Ethanolamine Between Octanol and Water Phases.pdf.pdf

Abstract

This study has investigated temperature dependence of octanol/water partition coefficients of cyclohexylamine and ethanolamine in temperature ranges of 5 to 25°C for cyclohexylamine and 17.5 to 25°C for ethanolamine. Experiments are largely based on a method developed by a researcher at the University of South Florida, which can help reduce chemical waste, save effort and time, and generate more reliable results. The study has found that the partition coefficient of cyclohexylamine is higher than that of ethanolamine, consistent with literature results. This also indicates that our approach is probably valid. By investigating correlation between chemical descriptors and partition coefficients of more than 1500 amine chemicals theoretically, we have shown that cyclohexylamine has higher values for descriptors that are positively correlated with logP. In addition, it has been found that temperature influences the partition coefficient of ethanolamine more than that of cyclohexylamine, probably due to smaller molecule size of ethanolamine. The partition coefficient of cyclohexylamine has a seemingly inverse relationship with temperature. On the other hand, temperature dependence of ethanolamine is more complicated. Moreover, we have determined thermodynamics of partition process including enthalpy, entropy, and free energy. Overall, these findings could be used to better assess their potential risks to public health.